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a04a1198 |
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12-Sep-2023 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: syscalls for current process attributes Create a system call lsm_get_self_attr() to provide the security module maintained attributes of the current process. Create a system call lsm_set_self_attr() to set a security module maintained attribute of the current process. Historically these attributes have been exposed to user space via entries in procfs under /proc/self/attr. The attribute value is provided in a lsm_ctx structure. The structure identifies the size of the attribute, and the attribute value. The format of the attribute value is defined by the security module. A flags field is included for LSM specific information. It is currently unused and must be 0. The total size of the data, including the lsm_ctx structure and any padding, is maintained as well. struct lsm_ctx { __u64 id; __u64 flags; __u64 len; __u64 ctx_len; __u8 ctx[]; }; Two new LSM hooks are used to interface with the LSMs. security_getselfattr() collects the lsm_ctx values from the LSMs that support the hook, accounting for space requirements. security_setselfattr() identifies which LSM the attribute is intended for and passes it along. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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f3b8788c |
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12-Sep-2023 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Identify modules by more than name Create a struct lsm_id to contain identifying information about Linux Security Modules (LSMs). At inception this contains the name of the module and an identifier associated with the security module. Change the security_add_hooks() interface to use this structure. Change the individual modules to maintain their own struct lsm_id and pass it to security_add_hooks(). The values are for LSM identifiers are defined in a new UAPI header file linux/lsm.h. Each existing LSM has been updated to include it's LSMID in the lsm_id. The LSM ID values are sequential, with the oldest module LSM_ID_CAPABILITY being the lowest value and the existing modules numbered in the order they were included in the main line kernel. This is an arbitrary convention for assigning the values, but none better presents itself. The value 0 is defined as being invalid. The values 1-99 are reserved for any special case uses which may arise in the future. This may include attributes of the LSM infrastructure itself, possibly related to namespacing or network attribute management. A special range is identified for such attributes to help reduce confusion for developers unfamiliar with LSMs. LSM attribute values are defined for the attributes presented by modules that are available today. As with the LSM IDs, The value 0 is defined as being invalid. The values 1-99 are reserved for any special case uses which may arise in the future. Cc: linux-security-module <linux-security-module@vger.kernel.org> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Mickael Salaun <mic@digikod.net> Reviewed-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Kees Cook <keescook@chromium.org> Nacked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> [PM: forward ported beyond v6.6 due merge window changes] Signed-off-by: Paul Moore <paul@paul-moore.com>
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6bcdfd2c |
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10-Jun-2023 |
Roberto Sassu <roberto.sassu@huawei.com> |
security: Allow all LSMs to provide xattrs for inode_init_security hook Currently, the LSM infrastructure supports only one LSM providing an xattr and EVM calculating the HMAC on that xattr, plus other inode metadata. Allow all LSMs to provide one or multiple xattrs, by extending the security blob reservation mechanism. Introduce the new lbs_xattr_count field of the lsm_blob_sizes structure, so that each LSM can specify how many xattrs it needs, and the LSM infrastructure knows how many xattr slots it should allocate. Modify the inode_init_security hook definition, by passing the full xattr array allocated in security_inode_init_security(), and the current number of xattr slots in that array filled by LSMs. The first parameter would allow EVM to access and calculate the HMAC on xattrs supplied by other LSMs, the second to not leave gaps in the xattr array, when an LSM requested but did not provide xattrs (e.g. if it is not initialized). Introduce lsm_get_xattr_slot(), which LSMs can call as many times as the number specified in the lbs_xattr_count field of the lsm_blob_sizes structure. During each call, lsm_get_xattr_slot() increments the number of filled xattrs, so that at the next invocation it returns the next xattr slot to fill. Cleanup security_inode_init_security(). Unify the !initxattrs and initxattrs case by simply not allocating the new_xattrs array in the former. Update the documentation to reflect the changes, and fix the description of the xattr name, as it is not allocated anymore. Adapt both SELinux and Smack to use the new definition of the inode_init_security hook, and to call lsm_get_xattr_slot() to obtain and fill the reserved slots in the xattr array. Move the xattr->name assignment after the xattr->value one, so that it is done only in case of successful memory allocation. Finally, change the default return value of the inode_init_security hook from zero to -EOPNOTSUPP, so that BPF LSM correctly follows the hook conventions. Reported-by: Nicolas Bouchinet <nicolas.bouchinet@clip-os.org> Link: https://lore.kernel.org/linux-integrity/Y1FTSIo+1x+4X0LS@archlinux/ Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> [PM: minor comment and variable tweaks, approved by RS] Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
34013331 |
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24-Mar-2023 |
Lukas Bulwahn <lukas.bulwahn@gmail.com> |
selinux: clean up dead code after removing runtime disable Commit f22f9aaf6c3d ("selinux: remove the runtime disable functionality") removes the config SECURITY_SELINUX_DISABLE. This results in some dead code in lsm_hooks.h. Remove this dead code. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
f22f9aaf |
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16-Mar-2023 |
Paul Moore <paul@paul-moore.com> |
selinux: remove the runtime disable functionality After working with the larger SELinux-based distros for several years, we're finally at a place where we can disable the SELinux runtime disable functionality. The existing kernel deprecation notice explains the functionality and why we want to remove it: The selinuxfs "disable" node allows SELinux to be disabled at runtime prior to a policy being loaded into the kernel. If disabled via this mechanism, SELinux will remain disabled until the system is rebooted. The preferred method of disabling SELinux is via the "selinux=0" boot parameter, but the selinuxfs "disable" node was created to make it easier for systems with primitive bootloaders that did not allow for easy modification of the kernel command line. Unfortunately, allowing for SELinux to be disabled at runtime makes it difficult to secure the kernel's LSM hooks using the "__ro_after_init" feature. It is that last sentence, mentioning the '__ro_after_init' hardening, which is the real motivation for this change, and if you look at the diffstat you'll see that the impact of this patch reaches across all the different LSMs, helping prevent tampering at the LSM hook level. From a SELinux perspective, it is important to note that if you continue to disable SELinux via "/etc/selinux/config" it may appear that SELinux is disabled, but it is simply in an uninitialized state. If you load a policy with `load_policy -i`, you will see SELinux come alive just as if you had loaded the policy during early-boot. It is also worth noting that the "/sys/fs/selinux/disable" file is always writable now, regardless of the Kconfig settings, but writing to the file has no effect on the system, other than to display an error on the console if a non-zero/true value is written. Finally, in the several years where we have been working on deprecating this functionality, there has only been one instance of someone mentioning any user visible breakage. In this particular case it was an individual's kernel test system, and the workaround documented in the deprecation notice ("selinux=0" on the kernel command line) resolved the issue without problem. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
42994ee3 |
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10-Mar-2023 |
Roberto Sassu <roberto.sassu@huawei.com> |
security: Introduce LSM_ORDER_LAST and set it for the integrity LSM Introduce LSM_ORDER_LAST, to satisfy the requirement of LSMs needing to be last, e.g. the 'integrity' LSM, without changing the kernel command line or configuration. Also, set this order for the 'integrity' LSM. While not enforced, this is the only LSM expected to use it. Similarly to LSM_ORDER_FIRST, LSMs with LSM_ORDER_LAST are always enabled and put at the end of the LSM list, if selected in the kernel configuration. Setting one of these orders alone, does not cause the LSMs to be selected and compiled built-in in the kernel. Finally, for LSM_ORDER_MUTABLE LSMs, set the found variable to true if an LSM is found, regardless of its order. In this way, the kernel would not wrongly report that the LSM is not built-in in the kernel if its order is LSM_ORDER_LAST. Fixes: 79f7865d844c ("LSM: Introduce "lsm=" for boottime LSM selection") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
e261301c |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the remaining LSM hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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1cd2aca6 |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the io_uring hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
452b670c |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the perf hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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55e85320 |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the bpf hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
b14faf9c |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the audit hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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1427ddbe |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the binder hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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43fad282 |
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16-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the sysv hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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ecc419a4 |
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15-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the key hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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742b9945 |
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15-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the xfrm hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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ac318aed |
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15-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the Infiniband hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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4a49f592 |
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15-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the SCTP hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
6b6bbe8c |
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12-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the socket hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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2c2442fd |
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12-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the AF_UNIX hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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2bcf51bf |
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12-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the netlink hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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130c53bf |
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11-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the task hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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a0fd6480 |
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10-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the file hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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9348944b |
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10-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the kernfs hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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916e3258 |
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08-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the inode hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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08526a90 |
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07-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the filesystem hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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36819f18 |
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07-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the fs_context hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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1661372c |
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07-Feb-2023 |
Paul Moore <paul@paul-moore.com> |
lsm: move the program execution hook comments to security/security.c This patch relocates the LSM hook function comments to the function definitions, in keeping with the current kernel conventions. This should make the hook descriptions more easily discoverable and easier to maintain. While formatting changes have been done to better fit the kernel-doc style, content changes have been kept to a minimum and limited to text which was obviously incorrect and/or outdated. It is expected the future patches will improve the quality of the function header comments. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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39f60c1c |
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12-Jan-2023 |
Christian Brauner <brauner@kernel.org> |
fs: port xattr to mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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577cc143 |
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09-Dec-2022 |
Roberto Sassu <roberto.sassu@huawei.com> |
lsm: Fix description of fs_context_parse_param The fs_context_parse_param hook already has a description, which seems the right one according to the code. Fixes: 8eb687bc8069 ("lsm: Add/fix return values in lsm_hooks.h and fix formatting") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
8eb687bc |
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28-Nov-2022 |
Roberto Sassu <roberto.sassu@huawei.com> |
lsm: Add/fix return values in lsm_hooks.h and fix formatting Ensure that for non-void LSM hooks there is a description of the return values. Also, replace spaces with tab for indentation, remove empty lines between the hook description and the list of parameters, adjust semicolons and add the period at the end of the parameter description. Finally, move the description of gfp parameter of the xfrm_policy_alloc_security hook together with the others. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> [PM: /replaces./replaced./] Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
361dd63e |
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28-Nov-2022 |
Roberto Sassu <roberto.sassu@huawei.com> |
lsm: Clarify documentation of vm_enough_memory hook include/linux/lsm_hooks.h reports the result of the LSM infrastructure to the callers, not what LSMs should return to the LSM infrastructure. Clarify that and add that if all LSMs return a positive value __vm_enough_memory() will be called with cap_sys_admin set. If at least one LSM returns 0 or negative, it will be called with cap_sys_admin cleared. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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b10b9c34 |
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09-Oct-2022 |
Paul Moore <paul@paul-moore.com> |
lsm: make security_socket_getpeersec_stream() sockptr_t safe Commit 4ff09db1b79b ("bpf: net: Change sk_getsockopt() to take the sockptr_t argument") made it possible to call sk_getsockopt() with both user and kernel address space buffers through the use of the sockptr_t type. Unfortunately at the time of conversion the security_socket_getpeersec_stream() LSM hook was written to only accept userspace buffers, and in a desire to avoid having to change the LSM hook the commit author simply passed the sockptr_t's userspace buffer pointer. Since the only sk_getsockopt() callers at the time of conversion which used kernel sockptr_t buffers did not allow SO_PEERSEC, and hence the security_socket_getpeersec_stream() hook, this was acceptable but also very fragile as future changes presented the possibility of silently passing kernel space pointers to the LSM hook. There are several ways to protect against this, including careful code review of future commits, but since relying on code review to catch bugs is a recipe for disaster and the upstream eBPF maintainer is "strongly against defensive programming", this patch updates the LSM hook, and all of the implementations to support sockptr_t and safely handle both user and kernel space buffers. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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3437d67a |
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25-Oct-2022 |
Gaosheng Cui <cuigaosheng1@huawei.com> |
lsm: remove obsoleted comments for security hooks Remove the following obsoleted comments for security hooks: 1. sb_copy_data, the hook function has been removed since commit 5b4002391153 ("LSM: turn sb_eat_lsm_opts() into a method"). 2. sb_parse_opts_str, the hook function has been removed since commit 757cbe597fe8 ("LSM: new method: ->sb_add_mnt_opt()"). They are obsoleted comments, so remove them. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> [PM: subj line tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
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72b3897e |
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22-Sep-2022 |
Christian Brauner <brauner@kernel.org> |
security: add get, remove and set acl hook The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. So far posix acls were passed as a void blob to the security and integrity modules. Some of them like evm then proceed to interpret the void pointer and convert it into the kernel internal struct posix acl representation to perform their integrity checking magic. This is obviously pretty problematic as that requires knowledge that only the vfs is guaranteed to have and has lead to various bugs. Add a proper security hook for setting posix acls and pass down the posix acls in their appropriate vfs format instead of hacking it through a void pointer stored in the uapi format. In the next patches we implement the hooks for the few security modules that do actually have restrictions on posix acls. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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3350607d |
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18-Oct-2022 |
Günther Noack <gnoack3000@gmail.com> |
security: Create file_truncate hook from path_truncate hook Like path_truncate, the file_truncate hook also restricts file truncation, but is called in the cases where truncation is attempted on an already-opened file. This is required in a subsequent commit to handle ftruncate() operations differently to truncate() operations. Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20221018182216.301684-2-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
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7cd4c5c2 |
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15-Aug-2022 |
Frederick Lawler <fred@cloudflare.com> |
security, lsm: Introduce security_create_user_ns() User namespaces are an effective tool to allow programs to run with permission without requiring the need for a program to run as root. User namespaces may also be used as a sandboxing technique. However, attackers sometimes leverage user namespaces as an initial attack vector to perform some exploit. [1,2,3] While it is not the unprivileged user namespace functionality, which causes the kernel to be exploitable, users/administrators might want to more granularly limit or at least monitor how various processes use this functionality, while vulnerable kernel subsystems are being patched. Preventing user namespace already creation comes in a few of forms in order of granularity: 1. /proc/sys/user/max_user_namespaces sysctl 2. Distro specific patch(es) 3. CONFIG_USER_NS To block a task based on its attributes, the LSM hook cred_prepare is a decent candidate for use because it provides more granular control, and it is called before create_user_ns(): cred = prepare_creds() security_prepare_creds() call_int_hook(cred_prepare, ... if (cred) create_user_ns(cred) Since security_prepare_creds() is meant for LSMs to copy and prepare credentials, access control is an unintended use of the hook. [4] Further, security_prepare_creds() will always return a ENOMEM if the hook returns any non-zero error code. This hook also does not handle the clone3 case which requires us to access a user space pointer to know if we're in the CLONE_NEW_USER call path which may be subject to a TOCTTOU attack. Lastly, cred_prepare is called in many call paths, and a targeted hook further limits the frequency of calls which is a beneficial outcome. Therefore introduce a new function security_create_user_ns() with an accompanying userns_create LSM hook. With the new userns_create hook, users will have more control over the observability and access control over user namespace creation. Users should expect that normal operation of user namespaces will behave as usual, and only be impacted when controls are implemented by users or administrators. This hook takes the prepared creds for LSM authors to write policy against. On success, the new namespace is applied to credentials, otherwise an error is returned. Links: 1. https://nvd.nist.gov/vuln/detail/CVE-2022-0492 2. https://nvd.nist.gov/vuln/detail/CVE-2022-25636 3. https://nvd.nist.gov/vuln/detail/CVE-2022-34918 4. https://lore.kernel.org/all/1c4b1c0d-12f6-6e9e-a6a3-cdce7418110c@schaufler-ca.com/ Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Reviewed-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Frederick Lawler <fred@cloudflare.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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2a584012 |
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15-Jul-2022 |
Luis Chamberlain <mcgrof@kernel.org> |
lsm,io_uring: add LSM hooks for the new uring_cmd file op io-uring cmd support was added through ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd"), this extended the struct file_operations to allow a new command which each subsystem can use to enable command passthrough. Add an LSM specific for the command passthrough which enables LSMs to inspect the command details. This was discussed long ago without no clear pointer for something conclusive, so this enables LSMs to at least reject this new file operation. [0] https://lkml.kernel.org/r/8adf55db-7bab-f59d-d612-ed906b948d19@schaufler-ca.com Cc: stable@vger.kernel.org Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd") Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paul Moore <paul@paul-moore.com>
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fcfe0ac2 |
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08-Jun-2022 |
Micah Morton <mortonm@chromium.org> |
security: Add LSM hook to setgroups() syscall Give the LSM framework the ability to filter setgroups() syscalls. There are already analagous hooks for the set*uid() and set*gid() syscalls. The SafeSetID LSM will use this new hook to ensure setgroups() calls are allowed by the installed security policy. Tested by putting print statement in security_task_fix_setgroups() hook and confirming that it gets hit when userspace does a setgroups() syscall. Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Micah Morton <mortonm@chromium.org>
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100f59d9 |
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06-May-2022 |
Mickaël Salaün <mic@digikod.net> |
LSM: Remove double path_rename hook calls for RENAME_EXCHANGE In order to be able to identify a file exchange with renameat2(2) and RENAME_EXCHANGE, which will be useful for Landlock [1], propagate the rename flags to LSMs. This may also improve performance because of the switch from two set of LSM hook calls to only one, and because LSMs using this hook may optimize the double check (e.g. only one lock, reduce the number of path walks). AppArmor, Landlock and Tomoyo are updated to leverage this change. This should not change the current behavior (same check order), except (different level of) speed boosts. [1] https://lore.kernel.org/r/20220221212522.320243-1-mic@digikod.net Cc: James Morris <jmorris@namei.org> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Serge E. Hallyn <serge@hallyn.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Mickaël Salaün <mic@digikod.net> Link: https://lore.kernel.org/r/20220506161102.525323-7-mic@digikod.net
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1af0e4a0 |
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17-Feb-2022 |
Christian Göttsche <cgzones@googlemail.com> |
security: declare member holding string literal const The struct security_hook_list member lsm is assigned in security_add_hooks() with string literals passed from the individual security modules. Declare the function parameter and the struct member const to signal their immutability. Reported by Clang [-Wwrite-strings]: security/selinux/hooks.c:7388:63: error: passing 'const char [8]' to parameter of type 'char *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers] security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), selinux); ^~~~~~~~~ ./include/linux/lsm_hooks.h:1629:11: note: passing argument to parameter 'lsm' here char *lsm); ^ Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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5e50f5d4 |
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12-Feb-2022 |
Ondrej Mosnacek <omosnace@redhat.com> |
security: add sctp_assoc_established hook security_sctp_assoc_established() is added to replace security_inet_conn_established() called in sctp_sf_do_5_1E_ca(), so that asoc can be accessed in security subsystem and save the peer secid to asoc->peer_secid. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad <pprahlad@redhat.com> Based-on-patch-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Tested-by: Richard Haines <richard_c_haines@btinternet.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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52f982f0 |
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06-Dec-2021 |
Ondrej Mosnacek <omosnace@redhat.com> |
security,selinux: remove security_add_mnt_opt() Its last user has been removed in commit f2aedb713c28 ("NFS: Add fs_context support."). Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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6326948f |
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29-Sep-2021 |
Paul Moore <paul@paul-moore.com> |
lsm: security_task_getsecid_subj() -> security_current_getsecid_subj() The security_task_getsecid_subj() LSM hook invites misuse by allowing callers to specify a task even though the hook is only safe when the current task is referenced. Fix this by removing the task_struct argument to the hook, requiring LSM implementations to use the current task. While we are changing the hook declaration we also rename the function to security_current_getsecid_subj() in an effort to reinforce that the hook captures the subjective credentials of the current task and not an arbitrary task on the system. Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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1aa3b220 |
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12-Nov-2021 |
Paul Moore <paul@paul-moore.com> |
net,lsm,selinux: revert the security_sctp_assoc_established() hook This patch reverts two prior patches, e7310c94024c ("security: implement sctp_assoc_established hook in selinux") and 7c2ef0240e6a ("security: add sctp_assoc_established hook"), which create the security_sctp_assoc_established() LSM hook and provide a SELinux implementation. Unfortunately these two patches were merged without proper review (the Reviewed-by and Tested-by tags from Richard Haines were for previous revisions of these patches that were significantly different) and there are outstanding objections from the SELinux maintainers regarding these patches. Work is currently ongoing to correct the problems identified in the reverted patches, as well as others that have come up during review, but it is unclear at this point in time when that work will be ready for inclusion in the mainline kernel. In the interest of not keeping objectionable code in the kernel for multiple weeks, and potentially a kernel release, we are reverting the two problematic patches. Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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32a370ab |
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11-Nov-2021 |
Paul Moore <paul@paul-moore.com> |
net,lsm,selinux: revert the security_sctp_assoc_established() hook This patch reverts two prior patches, e7310c94024c ("security: implement sctp_assoc_established hook in selinux") and 7c2ef0240e6a ("security: add sctp_assoc_established hook"), which create the security_sctp_assoc_established() LSM hook and provide a SELinux implementation. Unfortunately these two patches were merged without proper review (the Reviewed-by and Tested-by tags from Richard Haines were for previous revisions of these patches that were significantly different) and there are outstanding objections from the SELinux maintainers regarding these patches. Work is currently ongoing to correct the problems identified in the reverted patches, as well as others that have come up during review, but it is unclear at this point in time when that work will be ready for inclusion in the mainline kernel. In the interest of not keeping objectionable code in the kernel for multiple weeks, and potentially a kernel release, we are reverting the two problematic patches. Signed-off-by: Paul Moore <paul@paul-moore.com>
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7c2ef024 |
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02-Nov-2021 |
Xin Long <lucien.xin@gmail.com> |
security: add sctp_assoc_established hook security_sctp_assoc_established() is added to replace security_inet_conn_established() called in sctp_sf_do_5_1E_ca(), so that asoc can be accessed in security subsystem and save the peer secid to asoc->peer_secid. v1->v2: - fix the return value of security_sctp_assoc_established() in security.h, found by kernel test robot and Ondrej. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad <pprahlad@redhat.com> Reviewed-by: Richard Haines <richard_c_haines@btinternet.com> Tested-by: Richard Haines <richard_c_haines@btinternet.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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c081d53f |
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02-Nov-2021 |
Xin Long <lucien.xin@gmail.com> |
security: pass asoc to sctp_assoc_request and sctp_sk_clone This patch is to move secid and peer_secid from endpoint to association, and pass asoc to sctp_assoc_request and sctp_sk_clone instead of ep. As ep is the local endpoint and asoc represents a connection, and in SCTP one sk/ep could have multiple asoc/connection, saving secid/peer_secid for new asoc will overwrite the old asoc's. Note that since asoc can be passed as NULL, security_sctp_assoc_request() is moved to the place right after the new_asoc is created in sctp_sf_do_5_1B_init() and sctp_sf_do_unexpected_init(). v1->v2: - fix the description of selinux_netlbl_skbuff_setsid(), as Jakub noticed. - fix the annotation in selinux_sctp_assoc_request(), as Richard Noticed. Fixes: 72e89f50084c ("security: Add support for SCTP security hooks") Reported-by: Prashanth Prahlad <pprahlad@redhat.com> Reviewed-by: Richard Haines <richard_c_haines@btinternet.com> Tested-by: Richard Haines <richard_c_haines@btinternet.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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15bf3239 |
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12-Oct-2021 |
Vivek Goyal <vgoyal@redhat.com> |
security: Return xattr name from security_dentry_init_security() Right now security_dentry_init_security() only supports single security label and is used by SELinux only. There are two users of this hook, namely ceph and nfs. NFS does not care about xattr name. Ceph hardcodes the xattr name to security.selinux (XATTR_NAME_SELINUX). I am making changes to fuse/virtiofs to send security label to virtiofsd and I need to send xattr name as well. I also hardcoded the name of xattr to security.selinux. Stephen Smalley suggested that it probably is a good idea to modify security_dentry_init_security() to also return name of xattr so that we can avoid this hardcoding in the callers. This patch adds a new parameter "const char **xattr_name" to security_dentry_init_security() and LSM puts the name of xattr too if caller asked for it (xattr_name != NULL). Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: James Morris <jamorris@linux.microsoft.com> [PM: fixed typos in the commit description] Signed-off-by: Paul Moore <paul@paul-moore.com>
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52f88693 |
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12-Oct-2021 |
Todd Kjos <tkjos@google.com> |
binder: use cred instead of task for selinux checks Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Todd Kjos <tkjos@google.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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cdc1404a |
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01-Feb-2021 |
Paul Moore <paul@paul-moore.com> |
lsm,io_uring: add LSM hooks to io_uring A full expalantion of io_uring is beyond the scope of this commit description, but in summary it is an asynchronous I/O mechanism which allows for I/O requests and the resulting data to be queued in memory mapped "rings" which are shared between the kernel and userspace. Optionally, io_uring offers the ability for applications to spawn kernel threads to dequeue I/O requests from the ring and submit the requests in the kernel, helping to minimize the syscall overhead. Rings are accessed in userspace by memory mapping a file descriptor provided by the io_uring_setup(2), and can be shared between applications as one might do with any open file descriptor. Finally, process credentials can be registered with a given ring and any process with access to that ring can submit I/O requests using any of the registered credentials. While the io_uring functionality is widely recognized as offering a vastly improved, and high performing asynchronous I/O mechanism, its ability to allow processes to submit I/O requests with credentials other than its own presents a challenge to LSMs. When a process creates a new io_uring ring the ring's credentials are inhertied from the calling process; if this ring is shared with another process operating with different credentials there is the potential to bypass the LSMs security policy. Similarly, registering credentials with a given ring allows any process with access to that ring to submit I/O requests with those credentials. In an effort to allow LSMs to apply security policy to io_uring I/O operations, this patch adds two new LSM hooks. These hooks, in conjunction with the LSM anonymous inode support previously submitted, allow an LSM to apply access control policy to the sharing of io_uring rings as well as any io_uring credential changes requested by a process. The new LSM hooks are described below: * int security_uring_override_creds(cred) Controls if the current task, executing an io_uring operation, is allowed to override it's credentials with @cred. In cases where the current task is a user application, the current credentials will be those of the user application. In cases where the current task is a kernel thread servicing io_uring requests the current credentials will be those of the io_uring ring (inherited from the process that created the ring). * int security_uring_sqpoll(void) Controls if the current task is allowed to create an io_uring polling thread (IORING_SETUP_SQPOLL). Without a SQPOLL thread in the kernel processes must submit I/O requests via io_uring_enter(2) which allows us to compare any requested credential changes against the application making the request. With a SQPOLL thread, we can no longer compare requested credential changes against the application making the request, the comparison is made against the ring's credentials. Signed-off-by: Paul Moore <paul@paul-moore.com>
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83e804f0 |
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22-Apr-2021 |
Mickaël Salaün <mic@linux.microsoft.com> |
fs,security: Add sb_delete hook The sb_delete security hook is called when shutting down a superblock, which may be useful to release kernel objects tied to the superblock's lifetime (e.g. inodes). This new hook is needed by Landlock to release (ephemerally) tagged struct inodes. This comes from the unprivileged nature of Landlock described in the next commit. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: James Morris <jmorris@namei.org> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Reviewed-by: Jann Horn <jannh@google.com> Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210422154123.13086-7-mic@digikod.net Signed-off-by: James Morris <jamorris@linux.microsoft.com>
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1aea7808 |
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22-Apr-2021 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Infrastructure management of the superblock Move management of the superblock->sb_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules, the modules tell the infrastructure how much space is required, and the space is allocated there. Cc: John Johansen <john.johansen@canonical.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com> Acked-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210422154123.13086-6-mic@digikod.net Signed-off-by: James Morris <jamorris@linux.microsoft.com>
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4ebd7651 |
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19-Feb-2021 |
Paul Moore <paul@paul-moore.com> |
lsm: separate security_task_getsecid() into subjective and objective variants Of the three LSMs that implement the security_task_getsecid() LSM hook, all three LSMs provide the task's objective security credentials. This turns out to be unfortunate as most of the hook's callers seem to expect the task's subjective credentials, although a small handful of callers do correctly expect the objective credentials. This patch is the first step towards fixing the problem: it splits the existing security_task_getsecid() hook into two variants, one for the subjective creds, one for the objective creds. void security_task_getsecid_subj(struct task_struct *p, u32 *secid); void security_task_getsecid_obj(struct task_struct *p, u32 *secid); While this patch does fix all of the callers to use the correct variant, in order to keep this patch focused on the callers and to ease review, the LSMs continue to use the same implementation for both hooks. The net effect is that this patch should not change the behavior of the kernel in any way, it will be up to the latter LSM specific patches in this series to change the hook implementations and return the correct credentials. Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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69c4a42d |
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26-Feb-2021 |
Olga Kornievskaia <kolga@netapp.com> |
lsm,selinux: add new hook to compare new mount to an existing mount Add a new hook that takes an existing super block and a new mount with new options and determines if new options confict with an existing mount or not. A filesystem can use this new hook to determine if it can share the an existing superblock with a new superblock for the new mount. Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com> [PM: tweak the subject line, fix tab/space problems] Signed-off-by: Paul Moore <paul@paul-moore.com>
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71bc356f |
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21-Jan-2021 |
Christian Brauner <christian.brauner@ubuntu.com> |
commoncap: handle idmapped mounts When interacting with user namespace and non-user namespace aware filesystem capabilities the vfs will perform various security checks to determine whether or not the filesystem capabilities can be used by the caller, whether they need to be removed and so on. The main infrastructure for this resides in the capability codepaths but they are called through the LSM security infrastructure even though they are not technically an LSM or optional. This extends the existing security hooks security_inode_removexattr(), security_inode_killpriv(), security_inode_getsecurity() to pass down the mount's user namespace and makes them aware of idmapped mounts. In order to actually get filesystem capabilities from disk the capability infrastructure exposes the get_vfs_caps_from_disk() helper. For user namespace aware filesystem capabilities a root uid is stored alongside the capabilities. In order to determine whether the caller can make use of the filesystem capability or whether it needs to be ignored it is translated according to the superblock's user namespace. If it can be translated to uid 0 according to that id mapping the caller can use the filesystem capabilities stored on disk. If we are accessing the inode that holds the filesystem capabilities through an idmapped mount we map the root uid according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts: reading filesystem caps from disk enforces that the root uid associated with the filesystem capability must have a mapping in the superblock's user namespace and that the caller is either in the same user namespace or is a descendant of the superblock's user namespace. For filesystems that are mountable inside user namespace the caller can just mount the filesystem and won't usually need to idmap it. If they do want to idmap it they can create an idmapped mount and mark it with a user namespace they created and which is thus a descendant of s_user_ns. For filesystems that are not mountable inside user namespaces the descendant rule is trivially true because the s_user_ns will be the initial user namespace. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-11-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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215b674b |
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08-Jan-2021 |
Lokesh Gidra <lokeshgidra@google.com> |
security: add inode_init_security_anon() LSM hook This change adds a new LSM hook, inode_init_security_anon(), that will be used while creating secure anonymous inodes. The hook allows/denies its creation and assigns a security context to the inode. The new hook accepts an optional context_inode parameter that callers can use to provide additional contextual information to security modules for granting/denying permission to create an anon-inode of the same type. This context_inode's security_context can also be used to initialize the newly created anon-inode's security_context. Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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3df98d79 |
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27-Sep-2020 |
Paul Moore <paul@paul-moore.com> |
lsm,selinux: pass flowi_common instead of flowi to the LSM hooks As pointed out by Herbert in a recent related patch, the LSM hooks do not have the necessary address family information to use the flowi struct safely. As none of the LSMs currently use any of the protocol specific flowi information, replace the flowi pointers with pointers to the address family independent flowi_common struct. Reported-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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33def849 |
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21-Oct-2020 |
Joe Perches <joe@perches.com> |
treewide: Convert macro and uses of __section(foo) to __section("foo") Use a more generic form for __section that requires quotes to avoid complications with clang and gcc differences. Remove the quote operator # from compiler_attributes.h __section macro. Convert all unquoted __section(foo) uses to quoted __section("foo"). Also convert __attribute__((section("foo"))) uses to __section("foo") even if the __attribute__ has multiple list entry forms. Conversion done using the script at: https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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2039bda1 |
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02-Oct-2020 |
Kees Cook <keescook@chromium.org> |
LSM: Add "contents" flag to kernel_read_file hook As with the kernel_load_data LSM hook, add a "contents" flag to the kernel_read_file LSM hook that indicates whether the LSM can expect a matching call to the kernel_post_read_file LSM hook with the full contents of the file. With the coming addition of partial file read support for kernel_read_file*() API, the LSM will no longer be able to always see the entire contents of a file during the read calls. For cases where the LSM must read examine the complete file contents, it will need to do so on its own every time the kernel_read_file hook is called with contents=false (or reject such cases). Adjust all existing LSMs to retain existing behavior. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b64fcae7 |
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02-Oct-2020 |
Kees Cook <keescook@chromium.org> |
LSM: Introduce kernel_post_load_data() hook There are a few places in the kernel where LSMs would like to have visibility into the contents of a kernel buffer that has been loaded or read. While security_kernel_post_read_file() (which includes the buffer) exists as a pairing for security_kernel_read_file(), no such hook exists to pair with security_kernel_load_data(). Earlier proposals for just using security_kernel_post_read_file() with a NULL file argument were rejected (i.e. "file" should always be valid for the security_..._file hooks, but it appears at least one case was left in the kernel during earlier refactoring. (This will be fixed in a subsequent patch.) Since not all cases of security_kernel_load_data() can have a single contiguous buffer made available to the LSM hook (e.g. kexec image segments are separately loaded), there needs to be a way for the LSM to reason about its expectations of the hook coverage. In order to handle this, add a "contents" argument to the "kernel_load_data" hook that indicates if the newly added "kernel_post_load_data" hook will be called with the full contents once loaded. That way, LSMs requiring full contents can choose to unilaterally reject "kernel_load_data" with contents=false (which is effectively the existing hook coverage), but when contents=true they can allow it and later evaluate the "kernel_post_load_data" hook once the buffer is loaded. With this change, LSMs can gain coverage over non-file-backed data loads (e.g. init_module(2) and firmware userspace helper), which will happen in subsequent patches. Additionally prepare IMA to start processing these cases. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: KP Singh <kpsingh@google.com> Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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bb22d80b |
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17-Jul-2020 |
Randy Dunlap <rdunlap@infradead.org> |
LSM: drop duplicated words in header file comments Drop the doubled words "the" and "and" in comments. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Serge Hallyn <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org Signed-off-by: James Morris <jmorris@namei.org>
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39030e13 |
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09-Jun-2020 |
Thomas Cedeno <thomascedeno@google.com> |
security: Add LSM hooks to set*gid syscalls The SafeSetID LSM uses the security_task_fix_setuid hook to filter set*uid() syscalls according to its configured security policy. In preparation for adding analagous support in the LSM for set*gid() syscalls, we add the requisite hook here. Tested by putting print statements in the security_task_fix_setgid hook and seeing them get hit during kernel boot. Signed-off-by: Thomas Cedeno <thomascedeno@google.com> Signed-off-by: Micah Morton <mortonm@chromium.org>
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56305aa9 |
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29-May-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
exec: Compute file based creds only once Move the computation of creds from prepare_binfmt into begin_new_exec so that the creds need only be computed once. This is just code reorganization no semantic changes of any kind are made. Moving the computation is safe. I have looked through the kernel and verified none of the binfmts look at bprm->cred directly, and that there are no helpers that look at bprm->cred indirectly. Which means that it is not a problem to compute the bprm->cred later in the execution flow as it is not used until it becomes current->cred. A new function bprm_creds_from_file is added to contain the work that needs to be done. bprm_creds_from_file first computes which file bprm->executable or most likely bprm->file that the bprm->creds will be computed from. The funciton bprm_fill_uid is updated to receive the file instead of accessing bprm->file. The now unnecessary work needed to reset the bprm->cred->euid, and bprm->cred->egid is removed from brpm_fill_uid. A small comment to document that bprm_fill_uid now only deals with the work to handle suid and sgid files. The default case is already heandled by prepare_exec_creds. The function security_bprm_repopulate_creds is renamed security_bprm_creds_from_file and now is explicitly passed the file from which to compute the creds. The documentation of the bprm_creds_from_file security hook is updated to explain when the hook is called and what it needs to do. The file is passed from cap_bprm_creds_from_file into get_file_caps so that the caps are computed for the appropriate file. The now unnecessary work in cap_bprm_creds_from_file to reset the ambient capabilites has been removed. A small comment to document that the work of cap_bprm_creds_from_file is to read capabilities from the files secureity attribute and derive capabilities from the fact the user had uid 0 has been added. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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a7868323 |
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29-May-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
exec: Add a per bprm->file version of per_clear There is a small bug in the code that recomputes parts of bprm->cred for every bprm->file. The code never recomputes the part of clear_dangerous_personality_flags it is responsible for. Which means that in practice if someone creates a sgid script the interpreter will not be able to use any of: READ_IMPLIES_EXEC ADDR_NO_RANDOMIZE ADDR_COMPAT_LAYOUT MMAP_PAGE_ZERO. This accentially clearing of personality flags probably does not matter in practice because no one has complained but it does make the code more difficult to understand. Further remaining bug compatible prevents the recomputation from being removed and replaced by simply computing bprm->cred once from the final bprm->file. Making this change removes the last behavior difference between computing bprm->creds from the final file and recomputing bprm->cred several times. Which allows this behavior change to be justified for it's own reasons, and for any but hunts looking into why the behavior changed to wind up here instead of in the code that will follow that computes bprm->cred from the final bprm->file. This small logic bug appears to have existed since the code started clearing dangerous personality bits. History Tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Fixes: 1bb0fa189c6a ("[PATCH] NX: clean up legacy binary support") Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
112b7147 |
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13-May-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds Rename bprm->cap_elevated to bprm->active_secureexec and initialize it in prepare_binprm instead of in cap_bprm_set_creds. Initializing bprm->active_secureexec in prepare_binprm allows multiple implementations of security_bprm_repopulate_creds to play nicely with each other. Rename security_bprm_set_creds to security_bprm_reopulate_creds to emphasize that this path recomputes part of bprm->cred. This recomputation avoids the time of check vs time of use problems that are inherent in unix #! interpreters. In short two renames and a move in the location of initializing bprm->active_secureexec. Link: https://lkml.kernel.org/r/87o8qkzrxp.fsf_-_@x220.int.ebiederm.org Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
b8bff599 |
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22-Mar-2020 |
Eric W. Biederman <ebiederm@xmission.com> |
exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds Today security_bprm_set_creds has several implementations: apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds, smack_bprm_set_creds, and tomoyo_bprm_set_creds. Except for cap_bprm_set_creds they all test bprm->called_set_creds and return immediately if it is true. The function cap_bprm_set_creds ignores bprm->calld_sed_creds entirely. Create a new LSM hook security_bprm_creds_for_exec that is called just before prepare_binprm in __do_execve_file, resulting in a LSM hook that is called exactly once for the entire of exec. Modify the bits of security_bprm_set_creds that only want to be called once per exec into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds behind. Remove bprm->called_set_creds all of it's former users have been moved to security_bprm_creds_for_exec. Add or upate comments a appropriate to bring them up to date and to reflect this change. Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> # For the LSM and Smack bits Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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998f5040 |
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12-Feb-2020 |
David Howells <dhowells@redhat.com> |
security: Add hooks to rule on setting a watch Add security hooks that will allow an LSM to rule on whether or not a watch may be set. More than one hook is required as the watches watch different types of object. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jamorris@linux.microsoft.com> cc: Casey Schaufler <casey@schaufler-ca.com> cc: Stephen Smalley <sds@tycho.nsa.gov> cc: linux-security-module@vger.kernel.org
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344fa64e |
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12-Feb-2020 |
David Howells <dhowells@redhat.com> |
security: Add a hook for the point of notification insertion Add a security hook that allows an LSM to rule on whether a notification message is allowed to be inserted into a particular watch queue. The hook is given the following information: (1) The credentials of the triggerer (which may be init_cred for a system notification, eg. a hardware error). (2) The credentials of the whoever set the watch. (3) The notification message. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jamorris@linux.microsoft.com> cc: Casey Schaufler <casey@schaufler-ca.com> cc: Stephen Smalley <sds@tycho.nsa.gov> cc: linux-security-module@vger.kernel.org
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791a17ee |
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27-Apr-2020 |
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
docs: filesystems: convert mount_api.txt to ReST - Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add lists markups; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/32332c1659a28c22561cb5e64162c959856066b4.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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98e828a0 |
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28-Mar-2020 |
KP Singh <kpsingh@google.com> |
security: Refactor declaration of LSM hooks The information about the different types of LSM hooks is scattered in two locations i.e. union security_list_options and struct security_hook_heads. Rather than duplicating this information even further for BPF_PROG_TYPE_LSM, define all the hooks with the LSM_HOOK macro in lsm_hook_defs.h which is then used to generate all the data structures required by the LSM framework. The LSM hooks are defined as: LSM_HOOK(<return_type>, <default_value>, <hook_name>, args...) with <default_value> acccessible in security.c as: LSM_RET_DEFAULT(<hook_name>) Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Brendan Jackman <jackmanb@google.com> Reviewed-by: Florent Revest <revest@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/bpf/20200329004356.27286-3-kpsingh@chromium.org
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bd1a5a53 |
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16-Feb-2020 |
Randy Dunlap <rdunlap@infradead.org> |
security: <linux/lsm_hooks.h>: fix all kernel-doc warnings Fix all kernel-doc warnings in <linux/lsm_hooks.h>. Fixes the following warnings: ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'quotactl' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'quota_on' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'sb_free_mnt_opts' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'sb_eat_lsm_opts' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'sb_kern_mount' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'sb_show_options' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'sb_add_mnt_opt' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'd_instantiate' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'getprocattr' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'setprocattr' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'locked_down' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'perf_event_open' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'perf_event_alloc' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'perf_event_free' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'perf_event_read' not described in 'security_list_options' ../include/linux/lsm_hooks.h:1830: warning: Function parameter or member 'perf_event_write' not described in 'security_list_options' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: John Johansen <john.johansen@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Micah Morton <mortonm@chromium.org> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <jmorris@namei.org>
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da97e184 |
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14-Oct-2019 |
Joel Fernandes (Google) <joel@joelfernandes.org> |
perf_event: Add support for LSM and SELinux checks In current mainline, the degree of access to perf_event_open(2) system call depends on the perf_event_paranoid sysctl. This has a number of limitations: 1. The sysctl is only a single value. Many types of accesses are controlled based on the single value thus making the control very limited and coarse grained. 2. The sysctl is global, so if the sysctl is changed, then that means all processes get access to perf_event_open(2) opening the door to security issues. This patch adds LSM and SELinux access checking which will be used in Android to access perf_event_open(2) for the purposes of attaching BPF programs to tracepoints, perf profiling and other operations from userspace. These operations are intended for production systems. 5 new LSM hooks are added: 1. perf_event_open: This controls access during the perf_event_open(2) syscall itself. The hook is called from all the places that the perf_event_paranoid sysctl is checked to keep it consistent with the systctl. The hook gets passed a 'type' argument which controls CPU, kernel and tracepoint accesses (in this context, CPU, kernel and tracepoint have the same semantics as the perf_event_paranoid sysctl). Additionally, I added an 'open' type which is similar to perf_event_paranoid sysctl == 3 patch carried in Android and several other distros but was rejected in mainline [1] in 2016. 2. perf_event_alloc: This allocates a new security object for the event which stores the current SID within the event. It will be useful when the perf event's FD is passed through IPC to another process which may try to read the FD. Appropriate security checks will limit access. 3. perf_event_free: Called when the event is closed. 4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event. 5. perf_event_write: Called from the ioctl(2) syscalls for the event. [1] https://lwn.net/Articles/696240/ Since Peter had suggest LSM hooks in 2016 [1], I am adding his Suggested-by tag below. To use this patch, we set the perf_event_paranoid sysctl to -1 and then apply selinux checking as appropriate (default deny everything, and then add policy rules to give access to domains that need it). In the future we can remove the perf_event_paranoid sysctl altogether. Suggested-by: Peter Zijlstra <peterz@infradead.org> Co-developed-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: James Morris <jmorris@namei.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: rostedt@goodmis.org Cc: Yonghong Song <yhs@fb.com> Cc: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: jeffv@google.com Cc: Jiri Olsa <jolsa@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: primiano@google.com Cc: Song Liu <songliubraving@fb.com> Cc: rsavitski@google.com Cc: Namhyung Kim <namhyung@kernel.org> Cc: Matthew Garrett <matthewgarrett@google.com> Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
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9e47d31d |
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19-Aug-2019 |
Matthew Garrett <matthewgarrett@google.com> |
security: Add a "locked down" LSM hook Add a mechanism to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
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e6b1db98 |
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19-Aug-2019 |
Matthew Garrett <matthewgarrett@google.com> |
security: Support early LSMs The lockdown module is intended to allow for kernels to be locked down early in boot - sufficiently early that we don't have the ability to kmalloc() yet. Add support for early initialisation of some LSMs, and then add them to the list of names when we do full initialisation later. Early LSMs are initialised in link order and cannot be overridden via boot parameters, and cannot make use of kmalloc() (since the allocator isn't initialised yet). (Fixed by Stephen Rothwell to include a stub to fix builds when !CONFIG_SECURITY) Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: James Morris <jmorris@namei.org>
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ac5656d8 |
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12-Aug-2019 |
Aaron Goidel <acgoide@tycho.nsa.gov> |
fanotify, inotify, dnotify, security: add security hook for fs notifications As of now, setting watches on filesystem objects has, at most, applied a check for read access to the inode, and in the case of fanotify, requires CAP_SYS_ADMIN. No specific security hook or permission check has been provided to control the setting of watches. Using any of inotify, dnotify, or fanotify, it is possible to observe, not only write-like operations, but even read access to a file. Modeling the watch as being merely a read from the file is insufficient for the needs of SELinux. This is due to the fact that read access should not necessarily imply access to information about when another process reads from a file. Furthermore, fanotify watches grant more power to an application in the form of permission events. While notification events are solely, unidirectional (i.e. they only pass information to the receiving application), permission events are blocking. Permission events make a request to the receiving application which will then reply with a decision as to whether or not that action may be completed. This causes the issue of the watching application having the ability to exercise control over the triggering process. Without drawing a distinction within the permission check, the ability to read would imply the greater ability to control an application. Additionally, mount and superblock watches apply to all files within the same mount or superblock. Read access to one file should not necessarily imply the ability to watch all files accessed within a given mount or superblock. In order to solve these issues, a new LSM hook is implemented and has been placed within the system calls for marking filesystem objects with inotify, fanotify, and dnotify watches. These calls to the hook are placed at the point at which the target path has been resolved and are provided with the path struct, the mask of requested notification events, and the type of object on which the mark is being set (inode, superblock, or mount). The mask and obj_type have already been translated into common FS_* values shared by the entirety of the fs notification infrastructure. The path struct is passed rather than just the inode so that the mount is available, particularly for mount watches. This also allows for use of the hook by pathname-based security modules. However, since the hook is intended for use even by inode based security modules, it is not placed under the CONFIG_SECURITY_PATH conditional. Otherwise, the inode-based security modules would need to enable all of the path hooks, even though they do not use any of them. This only provides a hook at the point of setting a watch, and presumes that permission to set a particular watch implies the ability to receive all notification about that object which match the mask. This is all that is required for SELinux. If other security modules require additional hooks or infrastructure to control delivery of notification, these can be added by them. It does not make sense for us to propose hooks for which we have no implementation. The understanding that all notifications received by the requesting application are all strictly of a type for which the application has been granted permission shows that this implementation is sufficient in its coverage. Security modules wishing to provide complete control over fanotify must also implement a security_file_open hook that validates that the access requested by the watching application is authorized. Fanotify has the issue that it returns a file descriptor with the file mode specified during fanotify_init() to the watching process on event. This is already covered by the LSM security_file_open hook if the security module implements checking of the requested file mode there. Otherwise, a watching process can obtain escalated access to a file for which it has not been authorized. The selinux_path_notify hook implementation works by adding five new file permissions: watch, watch_mount, watch_sb, watch_reads, and watch_with_perm (descriptions about which will follow), and one new filesystem permission: watch (which is applied to superblock checks). The hook then decides which subset of these permissions must be held by the requesting application based on the contents of the provided mask and the obj_type. The selinux_file_open hook already checks the requested file mode and therefore ensures that a watching process cannot escalate its access through fanotify. The watch, watch_mount, and watch_sb permissions are the baseline permissions for setting a watch on an object and each are a requirement for any watch to be set on a file, mount, or superblock respectively. It should be noted that having either of the other two permissions (watch_reads and watch_with_perm) does not imply the watch, watch_mount, or watch_sb permission. Superblock watches further require the filesystem watch permission to the superblock. As there is no labeled object in view for mounts, there is no specific check for mount watches beyond watch_mount to the inode. Such a check could be added in the future, if a suitable labeled object existed representing the mount. The watch_reads permission is required to receive notifications from read-exclusive events on filesystem objects. These events include accessing a file for the purpose of reading and closing a file which has been opened read-only. This distinction has been drawn in order to provide a direct indication in the policy for this otherwise not obvious capability. Read access to a file should not necessarily imply the ability to observe read events on a file. Finally, watch_with_perm only applies to fanotify masks since it is the only way to set a mask which allows for the blocking, permission event. This permission is needed for any watch which is of this type. Though fanotify requires CAP_SYS_ADMIN, this is insufficient as it gives implicit trust to root, which we do not do, and does not support least privilege. Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
cb1aaebe |
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07-Jun-2019 |
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
docs: fix broken documentation links Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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#
8d93e952 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: lsm_hooks.h: fix documentation format Fix for name mismatch and omitted colons in the security_list_options documentation. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
9c53cb9d |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the shm_* hooks The shm_* hooks were changed in the commit "shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks" (7191adff2a55). The type of the argument shp was changed from shmid_kernel to kern_ipc_perm. This patch updates the documentation for the hooks accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
e9220bc8 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the sem_* hooks The sem_* hooks were changed in the commit "sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks" (aefad9593ec5). The type of the argument sma was changed from sem_array to kern_ipc_perm. This patch updates the documentation for the hooks accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
ab012bc8 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the msg_queue_* hooks The msg_queue_* hooks were changed in the commit "msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooks" (d8c6e8543294). The type of the argument msq was changed from msq_queue to kern_ipc_perm. This patch updates the documentation for the hooks accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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5fdd268f |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the audit_* hooks This patch updates the documentation for the audit_* hooks to use the same arguments names as in the hook's declarations. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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6b6b6476 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the path_chmod hook The path_chmod hook was changed in the commit "switch security_path_chmod() to struct path *" (cdcf116d44e7). The argument @mnt was removed from the hook, @dentry was changed to @path. This patch updates the documentation accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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2f991d7a |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the socket_getpeersec_dgram hook The socket_getpeersec_dgram hook was changed in the commit "[AF_UNIX]: Kernel memory leak fix for af_unix datagram getpeersec patch" (dc49c1f94e34). The arguments @secdata and @seclen were changed to @sock and @secid. This patch updates the documentation accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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a890e637 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the task_setscheduler hook The task_setscheduler hook was changed in the commit "security: remove unused parameter from security_task_setscheduler()" (b0ae19811375). The arguments @policy, @lp were removed from the hook. This patch updates the documentation accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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68b3edbd |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the socket_post_create hook This patch slightly fixes the documentation for the socket_post_create hook. The documentation states that i_security field is accessible through inode field of socket structure (i.e., 'sock->inode->i_security'). There is no inode field in the socket structure. The i_security field is accessible through SOCK_INODE macro. The patch updates the documentation to reflect this. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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5f4b9755 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for the syslog hook The syslog hook was changed in the commit "capabilities/syslog: open code cap_syslog logic to fix build failure" (12b3052c3ee8). The argument @from_file was removed from the hook. This patch updates the documentation for the syslog hook accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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733e4467 |
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26-Feb-2019 |
Denis Efremov <efremov@ispras.ru> |
LSM: fix documentation for sb_copy_data hook The @type argument of the sb_copy_data hook was removed in the commit "LSM/SELinux: Interfaces to allow FS to control mount options" (e0007529893c). This commit removes the description of the @type argument from the LSM documentation. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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24f7c45f |
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25-Mar-2019 |
Ondrej Mosnacek <omosnace@redhat.com> |
LSM: lsm_hooks.h - fix missing colon in docstring Apparently without it it is incorrect syntax and causes a warning about undocumented struct field. Fixes: b230d5aba2d1 ("LSM: add new hook for kernfs node initialization") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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b230d5ab |
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22-Feb-2019 |
Ondrej Mosnacek <omosnace@redhat.com> |
LSM: add new hook for kernfs node initialization This patch introduces a new security hook that is intended for initializing the security data for newly created kernfs nodes, which provide a way of storing a non-default security context, but need to operate independently from mounts (and therefore may not have an associated inode at the moment of creation). The main motivation is to allow kernfs nodes to inherit the context of the parent under SELinux, similar to the behavior of security_inode_init_security(). Other LSMs may implement their own logic for handling the creation of new nodes. This patch also adds helper functions to <linux/kernfs.h> for getting/setting security xattrs of a kernfs node so that LSMs hooks are able to do their job. Other important attributes should be accessible direcly in the kernfs_node fields (in case there is need for more, then new helpers should be added to kernfs.h along with the patch that needs them). Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> [PM: more manual merge fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
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2db154b3 |
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05-Nov-2018 |
David Howells <dhowells@redhat.com> |
vfs: syscall: Add move_mount(2) to move mounts around Add a move_mount() system call that will move a mount from one place to another and, in the next commit, allow to attach an unattached mount tree. The new system call looks like the following: int move_mount(int from_dfd, const char *from_path, int to_dfd, const char *to_path, unsigned int flags); Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-api@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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0b52075e |
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23-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
introduce cloning of fs_context new primitive: vfs_dup_fs_context(). Comes with fs_context method (->dup()) for copying the filesystem-specific parts of fs_context, along with LSM one (->fs_context_dup()) for doing the same to LSM parts. [needs better commit message, and change of Author:, anyway] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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da2441fd |
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01-Nov-2018 |
David Howells <dhowells@redhat.com> |
vfs: Add LSM hooks for the new mount API Add LSM hooks for use by the new mount API and filesystem context code. This includes: (1) Hooks to handle allocation, duplication and freeing of the security record attached to a filesystem context. (2) A hook to snoop source specifications. There may be multiple of these if the filesystem supports it. They will to be local files/devices if fs_context::source_is_dev is true and will be something else, possibly remote server specifications, if false. (3) A hook to snoop superblock configuration options in key[=val] form. If the LSM decides it wants to handle it, it can suppress the option being passed to the filesystem. Note that 'val' may include commas and binary data with the fsopen patch. (4) A hook to perform validation and allocation after the configuration has been done but before the superblock is allocated and set up. (5) A hook to transfer the security from the context to a newly created superblock. (6) A hook to rule on whether a path point can be used as a mountpoint. These are intended to replace: security_sb_copy_data security_sb_kern_mount security_sb_mount security_sb_set_mnt_opts security_sb_clone_mnt_opts security_sb_parse_opts_str [AV -- some of the methods being replaced are already gone, some of the methods are not added for the lack of need] Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-security-module@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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90462a5b |
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31-Jan-2019 |
Richard Guy Briggs <rgb@redhat.com> |
audit: remove unused actx param from audit_rule_match The audit_rule_match() struct audit_context *actx parameter is not used by any in-tree consumers (selinux, apparmour, integrity, smack). The audit context is an internal audit structure that should only be accessed by audit accessor functions. It was part of commit 03d37d25e0f9 ("LSM/Audit: Introduce generic Audit LSM hooks") but appears to have never been used. Remove it. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/107 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: fixed the referenced commit title] Signed-off-by: Paul Moore <paul@paul-moore.com>
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1cfb2a51 |
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18-Jan-2019 |
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
LSM: Make lsm_early_cred() and lsm_early_task() local functions. Since current->cred == current->real_cred when ordered_lsm_init() is called, and lsm_early_cred()/lsm_early_task() need to be called between the amount of required bytes is determined and module specific initialization function is called, we can move these calls from individual modules to ordered_lsm_init(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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c1a85a00 |
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07-Jan-2019 |
Micah Morton <mortonm@chromium.org> |
LSM: generalize flag passing to security_capable This patch provides a general mechanism for passing flags to the security_capable LSM hook. It replaces the specific 'audit' flag that is used to tell security_capable whether it should log an audit message for the given capability check. The reason for generalizing this flag passing is so we can add an additional flag that signifies whether security_capable is being called by a setid syscall (which is needed by the proposed SafeSetID LSM). Signed-off-by: Micah Morton <mortonm@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com>
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ecd5f82e |
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20-Nov-2018 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Infrastructure management of the ipc security blob Move management of the kern_ipc_perm->security and msg_msg->security blobs out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
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f4ad8f2c |
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21-Sep-2018 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Infrastructure management of the task security Move management of the task_struct->security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. The only user of this blob is AppArmor. The AppArmor use is abstracted to avoid future conflict. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
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afb1cbe3 |
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21-Sep-2018 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Infrastructure management of the inode security Move management of the inode->i_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
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33bf60ca |
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12-Nov-2018 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Infrastructure management of the file security Move management of the file->f_security blob out of the individual security modules and into the infrastructure. The modules no longer allocate or free the data, instead they tell the infrastructure how much space they require. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
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bbd3662a |
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12-Nov-2018 |
Casey Schaufler <casey@schaufler-ca.com> |
Infrastructure management of the cred security blob Move management of the cred security blob out of the security modules and into the security infrastructre. Instead of allocating and freeing space the security modules tell the infrastructure how much space they require. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
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d117a154 |
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14-Sep-2018 |
Kees Cook <keescook@chromium.org> |
capability: Initialize as LSM_ORDER_FIRST This converts capabilities to use the new LSM_ORDER_FIRST position. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
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e2bc445b |
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19-Sep-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Introduce enum lsm_order In preparation for distinguishing the "capability" LSM from other LSMs, it must be ordered first. This introduces LSM_ORDER_MUTABLE for the general LSMs and LSM_ORDER_FIRST for capability. In the future LSM_ORDER_LAST for could be added for anything that must run last (e.g. Landlock may use this). Signed-off-by: Kees Cook <keescook@chromium.org>
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d6aed64b |
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14-Sep-2018 |
Kees Cook <keescook@chromium.org> |
Yama: Initialize as ordered LSM This converts Yama from being a direct "minor" LSM into an ordered LSM. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
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70b62c25 |
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14-Sep-2018 |
Kees Cook <keescook@chromium.org> |
LoadPin: Initialize as ordered LSM This converts LoadPin from being a direct "minor" LSM into an ordered LSM. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
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14bd99c8 |
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19-Sep-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Separate idea of "major" LSM from "exclusive" LSM In order to both support old "security=" Legacy Major LSM selection, and handling real exclusivity, this creates LSM_FLAG_EXCLUSIVE and updates the selection logic to handle them. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
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a8027fb0 |
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09-Oct-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Tie enabling logic to presence in ordered list Until now, any LSM without an enable storage variable was considered enabled. This inverts the logic and sets defaults to true only if the LSM gets added to the ordered initialization list. (And an exception continues for the major LSMs until they are integrated into the ordered initialization in a later patch.) Signed-off-by: Kees Cook <keescook@chromium.org>
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f4941d75 |
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14-Sep-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Lift LSM selection out of individual LSMs As a prerequisite to adjusting LSM selection logic in the future, this moves the selection logic up out of the individual major LSMs, making their init functions only run when actually enabled. This considers all LSMs enabled by default unless they specified an external "enable" variable. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
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c5459b82 |
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13-Sep-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Plumb visibility into optional "enabled" state In preparation for lifting the "is this LSM enabled?" logic out of the individual LSMs, pass in any special enabled state tracking (as needed for SELinux, AppArmor, and LoadPin). This should be an "int" to include handling any future cases where "enabled" is exposed via sysctl which has no "bool" type. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
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47008e51 |
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19-Sep-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Introduce LSM_FLAG_LEGACY_MAJOR This adds a flag for the current "major" LSMs to distinguish them when we have a universal method for ordering all LSMs. It's called "legacy" since the distinction of "major" will go away in the blob-sharing world. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
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757cbe59 |
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14-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
LSM: new method: ->sb_add_mnt_opt() Adding options to growing mnt_opts. NFS kludge with passing context= down into non-text-options mount switched to it, and with that the last use of ->sb_parse_opts_str() is gone. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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204cc0cc |
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13-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
LSM: hide struct security_mnt_opts from any generic code Keep void * instead, allocate on demand (in parse_str_opts, at the moment). Eventually both selinux and smack will be better off with private structures with several strings in those, rather than this "counter and two pointers to dynamically allocated arrays" ugliness. This commit allows to do that at leisure, without disrupting anything outside of given module. Changes: * instead of struct security_mnt_opt use an opaque pointer initialized to NULL. * security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and security_free_mnt_opts() take it as var argument (i.e. as void **); call sites are unchanged. * security_sb_set_mnt_opts() and security_sb_remount() take it by value (i.e. as void *). * new method: ->sb_free_mnt_opts(). Takes void *, does whatever freeing that needs to be done. * ->sb_set_mnt_opts() and ->sb_remount() might get NULL as mnt_opts argument, meaning "empty". Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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5b400239 |
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12-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
LSM: turn sb_eat_lsm_opts() into a method Kill ->sb_copy_data() - it's used only in combination with immediately following ->sb_parse_opts_str(). Turn that combination into a new method. This is just a mechanical move - cleanups will be the next step. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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a10d7c22 |
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05-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount() ... leaving the "is it kernel-internal" logics in the caller. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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c039bc3c |
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01-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
LSM: lift extracting and parsing LSM options into the caller of ->sb_remount() This paves the way for retaining the LSM options from a common filesystem mount context during a mount parameter parsing phase to be instituted prior to actual mount/reconfiguration actions. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
6be8750b |
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01-Dec-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
LSM: lift parsing LSM options into the caller of ->sb_kern_mount() This paves the way for retaining the LSM options from a common filesystem mount context during a mount parameter parsing phase to be instituted prior to actual mount/reconfiguration actions. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
07aed2f2 |
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10-Oct-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Record LSM name in struct lsm_info In preparation for making LSM selections outside of the LSMs, include the name of LSMs in struct lsm_info. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
3d6e5f6d |
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10-Oct-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Convert security_initcall() into DEFINE_LSM() Instead of using argument-based initializers, switch to defining the contents of struct lsm_info on a per-LSM basis. This also drops the final use of the now inaccurate "initcall" naming. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <james.morris@microsoft.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
5b89c1bd |
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10-Oct-2018 |
Kees Cook <keescook@chromium.org> |
LSM: Convert from initcall to struct lsm_info In preparation for doing more interesting LSM init probing, this converts the existing initcall system into an explicit call into a function pointer from a section-collected struct lsm_info array. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <james.morris@microsoft.com> Reviewed-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
ae7795bc |
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25-Sep-2018 |
Eric W. Biederman <ebiederm@xmission.com> |
signal: Distinguish between kernel_siginfo and siginfo Linus recently observed that if we did not worry about the padding member in struct siginfo it is only about 48 bytes, and 48 bytes is much nicer than 128 bytes for allocating on the stack and copying around in the kernel. The obvious thing of only adding the padding when userspace is including siginfo.h won't work as there are sigframe definitions in the kernel that embed struct siginfo. So split siginfo in two; kernel_siginfo and siginfo. Keeping the traditional name for the userspace definition. While the version that is used internally to the kernel and ultimately will not be padded to 128 bytes is called kernel_siginfo. The definition of struct kernel_siginfo I have put in include/signal_types.h A set of buildtime checks has been added to verify the two structures have the same field offsets. To make it easy to verify the change kernel_siginfo retains the same size as siginfo. The reduction in size comes in a following change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
377179cd |
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13-Jul-2018 |
Mimi Zohar <zohar@linux.vnet.ibm.com> |
security: define new LSM hook named security_kernel_load_data Differentiate between the kernel reading a file specified by userspace from the kernel loading a buffer containing data provided by userspace. This patch defines a new LSM hook named security_kernel_load_data(). Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
94817692 |
|
10-Jul-2018 |
Al Viro <viro@zeniv.linux.org.uk> |
->file_open(): lose cred argument Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
aae7cfcb |
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04-May-2018 |
David Herrmann <dh.herrmann@gmail.com> |
security: add hook for socketpair() Right now the LSM labels for socketpairs are always uninitialized, since there is no security hook for the socketpair() syscall. This patch adds the required hooks so LSMs can properly label socketpairs. This allows SO_PEERSEC to return useful information on those sockets. Note that the behavior of socketpair() can be emulated by creating a listener socket, connecting to it, and then discarding the initial listener socket. With this workaround, SO_PEERSEC would return the caller's security context. However, with socketpair(), the uninitialized context is returned unconditionally. This is unexpected and makes socketpair() less useful in situations where the security context is crucial to the application. With the new socketpair-hook this disparity can be solved by making socketpair() return the expected security context. Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Tom Gundersen <teg@jklm.no> Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
df0ce173 |
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28-Mar-2018 |
Sargun Dhillon <sargun@sargun.me> |
security: convert security hooks to use hlist This changes security_hook_heads to use hlist_heads instead of the circular doubly-linked list heads. This should cut down the size of the struct by about half. In addition, it allows mutation of the hooks at the tail of the callback list without having to modify the head. The longer-term purpose of this is to enable making the heads read only. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Reviewed-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
3ec30113 |
|
08-Jan-2018 |
Matthew Garrett <mjg59@google.com> |
security: Add a cred_getsecid hook For IMA purposes, we want to be able to obtain the prepared secid in the bprm structure before the credentials are committed. Add a cred_getsecid hook that makes this possible. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
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#
d8c6e854 |
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22-Mar-2018 |
Eric W. Biederman <ebiederm@xmission.com> |
msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooks All of the implementations of security hooks that take msg_queue only access q_perm the struct kern_ipc_perm member. This means the dependencies of the msg_queue security hooks can be simplified by passing the kern_ipc_perm member of msg_queue. Making this change will allow struct msg_queue to become private to ipc/msg.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
7191adff |
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22-Mar-2018 |
Eric W. Biederman <ebiederm@xmission.com> |
shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks All of the implementations of security hooks that take shmid_kernel only access shm_perm the struct kern_ipc_perm member. This means the dependencies of the shm security hooks can be simplified by passing the kern_ipc_perm member of shmid_kernel.. Making this change will allow struct shmid_kernel to become private to ipc/shm.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
aefad959 |
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22-Mar-2018 |
Eric W. Biederman <ebiederm@xmission.com> |
sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks All of the implementations of security hooks that take sem_array only access sem_perm the struct kern_ipc_perm member. This means the dependencies of the sem security hooks can be simplified by passing the kern_ipc_perm member of sem_array. Making this change will allow struct sem and struct sem_array to become private to ipc/sem.c. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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#
6b4f3d01 |
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07-Sep-2017 |
Stephen Smalley <sds@tycho.nsa.gov> |
usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill commit d178bc3a708f39cbfefc3fab37032d3f2511b4ec ("user namespace: usb: make usb urbs user namespace aware (v2)") changed kill_pid_info_as_uid to kill_pid_info_as_cred, saving and passing a cred structure instead of uids. Since the secid can be obtained from the cred, drop the secid fields from the usb_dev_state and async structures, and drop the secid argument to kill_pid_info_as_cred. Replace the secid argument to security_task_kill with the cred. Update SELinux, Smack, and AppArmor to use the cred, which avoids the need for Smack and AppArmor to use a secid at all in this hook. Further changes to Smack might still be required to take full advantage of this change, since it should now be possible to perform capability checking based on the supplied cred. The changes to Smack and AppArmor have only been compile-tested. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <james.morris@microsoft.com>
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#
72e89f50 |
|
13-Feb-2018 |
Richard Haines <richard_c_haines@btinternet.com> |
security: Add support for SCTP security hooks The SCTP security hooks are explained in: Documentation/security/LSM-sctp.rst Signed-off-by: Richard Haines <richard_c_haines@btinternet.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
afdb09c7 |
|
18-Oct-2017 |
Chenbo Feng <fengc@google.com> |
security: bpf: Add LSM hooks for bpf object related syscall Introduce several LSM hooks for the syscalls that will allow the userspace to access to eBPF object such as eBPF programs and eBPF maps. The security check is aimed to enforce a per object security protection for eBPF object so only processes with the right priviliges can read/write to a specific map or use a specific eBPF program. Besides that, a general security hook is added before the multiplexer of bpf syscall to check the cmd and the attribute used for the command. The actual security module can decide which command need to be checked and how the cmd should be checked. Signed-off-by: Chenbo Feng <fengc@google.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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#
2af62280 |
|
18-Jul-2017 |
Kees Cook <keescook@chromium.org> |
LSM: drop bprm_secureexec hook This removes the bprm_secureexec hook since the logic has been folded into the bprm_set_creds hook for all LSMs now. Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: John Johansen <john.johansen@canonical.com> Acked-by: James Morris <james.l.morris@oracle.com> Acked-by: Serge Hallyn <serge@hallyn.com>
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#
3cf29931 |
|
14-Jul-2017 |
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
LSM: Remove security_task_create() hook. Since commit a79be238600d1a03 ("selinux: Use task_alloc hook rather than task_create hook") changed to use task_alloc hook, task_create hook is no longer used. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
3859a271 |
|
28-Oct-2016 |
Kees Cook <keescook@chromium.org> |
randstruct: Mark various structs for randomization This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
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#
0b4d3452 |
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05-Jun-2017 |
Scott Mayhew <smayhew@redhat.com> |
security/selinux: allow security_sb_clone_mnt_opts to enable/disable native labeling behavior When an NFSv4 client performs a mount operation, it first mounts the NFSv4 root and then does path walk to the exported path and performs a submount on that, cloning the security mount options from the root's superblock to the submount's superblock in the process. Unless the NFS server has an explicit fsid=0 export with the "security_label" option, the NFSv4 root superblock will not have SBLABEL_MNT set, and neither will the submount superblock after cloning the security mount options. As a result, setxattr's of security labels over NFSv4.2 will fail. In a similar fashion, NFSv4.2 mounts mounted with the context= mount option will not show the correct labels because the nfs_server->caps flags of the cloned superblock will still have NFS_CAP_SECURITY_LABEL set. Allowing the NFSv4 client to enable or disable SECURITY_LSM_NATIVE_LABELS behavior will ensure that the SBLABEL_MNT flag has the correct value when the client traverses from an exported path without the "security_label" option to one with the "security_label" option and vice versa. Similarly, checking to see if SECURITY_LSM_NATIVE_LABELS is set upon return from security_sb_clone_mnt_opts() and clearing NFS_CAP_SECURITY_LABEL if necessary will allow the correct labels to be displayed for NFSv4.2 mounts mounted with the context= mount option. Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/35 Signed-off-by: Scott Mayhew <smayhew@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Tested-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
47a2b338 |
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19-May-2017 |
Daniel Jurgens <danielj@mellanox.com> |
IB/core: Enforce security on management datagrams Allocate and free a security context when creating and destroying a MAD agent. This context is used for controlling access to PKeys and sending and receiving SMPs. When sending or receiving a MAD check that the agent has permission to access the PKey for the Subnet Prefix of the port. During MAD and snoop agent registration for SMI QPs check that the calling process has permission to access the manage the subnet and register a callback with the LSM to be notified of policy changes. When notificaiton of a policy change occurs recheck permission and set a flag indicating sending and receiving SMPs is allowed. When sending and receiving MADs check that the agent has access to the SMI if it's on an SMI QP. Because security policy can change it's possible permission was allowed when creating the agent, but no longer is. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Acked-by: Doug Ledford <dledford@redhat.com> [PM: remove the LSM hook init code] Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
d291f1a6 |
|
19-May-2017 |
Daniel Jurgens <danielj@mellanox.com> |
IB/core: Enforce PKey security on QPs Add new LSM hooks to allocate and free security contexts and check for permission to access a PKey. Allocate and free a security context when creating and destroying a QP. This context is used for controlling access to PKeys. When a request is made to modify a QP that changes the port, PKey index, or alternate path, check that the QP has permission for the PKey in the PKey table index on the subnet prefix of the port. If the QP is shared make sure all handles to the QP also have access. Store which port and PKey index a QP is using. After the reset to init transition the user can modify the port, PKey index and alternate path independently. So port and PKey settings changes can be a merge of the previous settings and the new ones. In order to maintain access control if there are PKey table or subnet prefix change keep a list of all QPs are using each PKey index on each port. If a change occurs all QPs using that device and port must have access enforced for the new cache settings. These changes add a transaction to the QP modify process. Association with the old port and PKey index must be maintained if the modify fails, and must be removed if it succeeds. Association with the new port and PKey index must be established prior to the modify and removed if the modify fails. 1. When a QP is modified to a particular Port, PKey index or alternate path insert that QP into the appropriate lists. 2. Check permission to access the new settings. 3. If step 2 grants access attempt to modify the QP. 4a. If steps 2 and 3 succeed remove any prior associations. 4b. If ether fails remove the new setting associations. If a PKey table or subnet prefix changes walk the list of QPs and check that they have permission. If not send the QP to the error state and raise a fatal error event. If it's a shared QP make sure all the QPs that share the real_qp have permission as well. If the QP that owns a security structure is denied access the security structure is marked as such and the QP is added to an error_list. Once the moving the QP to error is complete the security structure mark is cleared. Maintaining the lists correctly turns QP destroy into a transaction. The hardware driver for the device frees the ib_qp structure, so while the destroy is in progress the ib_qp pointer in the ib_qp_security struct is undefined. When the destroy process begins the ib_qp_security structure is marked as destroying. This prevents any action from being taken on the QP pointer. After the QP is destroyed successfully it could still listed on an error_list wait for it to be processed by that flow before cleaning up the structure. If the destroy fails the QPs port and PKey settings are reinserted into the appropriate lists, the destroying flag is cleared, and access control is enforced, in case there were any cache changes during the destroy flow. To keep the security changes isolated a new file is used to hold security related functionality. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Acked-by: Doug Ledford <dledford@redhat.com> [PM: merge fixup in ib_verbs.h and uverbs_cmd.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
f00f85a8 |
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13-May-2017 |
Kees Cook <keescook@chromium.org> |
doc: security: minor cleanups to build kernel-doc These fixes were needed to parse lsm_hooks.h kernel-doc. More work is needed, but this is the first step. Acked-by: James Morris <james.l.morris@oracle.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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#
e4e55b47 |
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24-Mar-2017 |
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
LSM: Revive security_task_alloc() hook and per "struct task_struct" security blob. We switched from "struct task_struct"->security to "struct cred"->security in Linux 2.6.29. But not all LSM modules were happy with that change. TOMOYO LSM module is an example which want to use per "struct task_struct" security blob, for TOMOYO's security context is defined based on "struct task_struct" rather than "struct cred". AppArmor LSM module is another example which want to use it, for AppArmor is currently abusing the cred a little bit to store the change_hat and setexeccon info. Although security_task_free() hook was revived in Linux 3.4 because Yama LSM module wanted to release per "struct task_struct" security blob, security_task_alloc() hook and "struct task_struct"->security field were not revived. Nowadays, we are getting proposals of lightweight LSM modules which want to use per "struct task_struct" security blob. We are already allowing multiple concurrent LSM modules (up to one fully armored module which uses "struct cred"->security field or exclusive hooks like security_xfrm_state_pol_flow_match(), plus unlimited number of lightweight modules which do not use "struct cred"->security nor exclusive hooks) as long as they are built into the kernel. But this patch does not implement variable length "struct task_struct"->security field which will become needed when multiple LSM modules want to use "struct task_struct"-> security field. Although it won't be difficult to implement variable length "struct task_struct"->security field, let's think about it after we merged this patch. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Djalal Harouni <tixxdz@gmail.com> Acked-by: José Bollo <jobol@nonadev.net> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Kees Cook <keescook@chromium.org> Cc: James Morris <james.l.morris@oracle.com> Cc: José Bollo <jobol@nonadev.net> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
dd0859dc |
|
14-Feb-2017 |
James Morris <jmorris@namei.org> |
security: introduce CONFIG_SECURITY_WRITABLE_HOOKS Subsequent patches will add RO hardening to LSM hooks, however, SELinux still needs to be able to perform runtime disablement after init to handle architectures where init-time disablement via boot parameters is not feasible. Introduce a new kernel configuration parameter CONFIG_SECURITY_WRITABLE_HOOKS, and a helper macro __lsm_ro_after_init, to handle this case. Signed-off-by: James Morris <james.l.morris@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Kees Cook <keescook@chromium.org>
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#
791ec491 |
|
17-Feb-2017 |
Stephen Smalley <sds@tycho.nsa.gov> |
prlimit,security,selinux: add a security hook for prlimit When SELinux was first added to the kernel, a process could only get and set its own resource limits via getrlimit(2) and setrlimit(2), so no MAC checks were required for those operations, and thus no security hooks were defined for them. Later, SELinux introduced a hook for setlimit(2) with a check if the hard limit was being changed in order to be able to rely on the hard limit value as a safe reset point upon context transitions. Later on, when prlimit(2) was added to the kernel with the ability to get or set resource limits (hard or soft) of another process, LSM/SELinux was not updated other than to pass the target process to the setrlimit hook. This resulted in incomplete control over both getting and setting the resource limits of another process. Add a new security_task_prlimit() hook to the check_prlimit_permission() function to provide complete mediation. The hook is only called when acting on another task, and only if the existing DAC/capability checks would allow access. Pass flags down to the hook to indicate whether the prlimit(2) call will read, write, or both read and write the resource limits of the target process. The existing security_task_setrlimit() hook is left alone; it continues to serve a purpose in supporting the ability to make decisions based on the old and/or new resource limit values when setting limits. This is consistent with the DAC/capability logic, where check_prlimit_permission() performs generic DAC/capability checks for acting on another task, while do_prlimit() performs a capability check based on a comparison of the old and new resource limits. Fix the inline documentation for the hook to match the code. Implement the new hook for SELinux. For setting resource limits, we reuse the existing setrlimit permission. Note that this does overload the setrlimit permission to mean the ability to set the resource limit (soft or hard) of another process or the ability to change one's own hard limit. For getting resource limits, a new getrlimit permission is defined. This was not originally defined since getrlimit(2) could only be used to obtain a process' own limits. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
d69dece5 |
|
18-Jan-2017 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Add /sys/kernel/security/lsm I am still tired of having to find indirect ways to determine what security modules are active on a system. I have added /sys/kernel/security/lsm, which contains a comma separated list of the active security modules. No more groping around in /proc/filesystems or other clever hacks. Unchanged from previous versions except for being updated to the latest security next branch. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
3a2f5a59 |
|
09-Jan-2017 |
Stephen Smalley <sds@tycho.nsa.gov> |
security,selinux,smack: kill security_task_wait hook As reported by yangshukui, a permission denial from security_task_wait() can lead to a soft lockup in zap_pid_ns_processes() since it only expects sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can in general lead to zombies; in the absence of some way to automatically reparent a child process upon a denial, the hook is not useful. Remove the security hook and its implementations in SELinux and Smack. Smack already removed its check from its hook. Reported-by: yangshukui <yangshukui@huawei.com> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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#
b8aa8453 |
|
21-Dec-2016 |
Mickaël Salaün <mic@digikod.net> |
security: Fix inode_getattr documentation Replace arguments @mnt and @dentry with @path. Signed-off-by: Mickaël Salaün <mic@digikod.net> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
b21507e2 |
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09-Jan-2017 |
Stephen Smalley <sds@tycho.nsa.gov> |
proc,security: move restriction on writing /proc/pid/attr nodes to proc Processes can only alter their own security attributes via /proc/pid/attr nodes. This is presently enforced by each individual security module and is also imposed by the Linux credentials implementation, which only allows a task to alter its own credentials. Move the check enforcing this restriction from the individual security modules to proc_pid_attr_write() before calling the security hook, and drop the unnecessary task argument to the security hook since it can only ever be the current task. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
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a4f4528a |
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09-Jul-2016 |
Mickaël Salaün <mic@digikod.net> |
module: Fully remove the kernel_module_from_file hook Remove remaining kernel_module_from_file hook left by commit a1db74209483 ("module: replace copy_module_from_fd with kernel version") Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
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2602625b |
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13-Jul-2016 |
Vivek Goyal <vgoyal@redhat.com> |
security, overlayfs: Provide hook to correctly label newly created files During a new file creation we need to make sure new file is created with the right label. New file is created in upper/ so effectively file should get label as if task had created file in upper/. We switched to mounter's creds for actual file creation. Also if there is a whiteout present, then file will be created in work/ dir first and then renamed in upper. In none of the cases file will be labeled as we want it to be. This patch introduces a new hook dentry_create_files_as(), which determines the label/context dentry will get if it had been created by task in upper and modify passed set of creds appropriately. Caller makes use of these new creds for file creation. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: fix whitespace issues found with checkpatch.pl] [PM: changes to use stat->mode in ovl_create_or_link()] Signed-off-by: Paul Moore <paul@paul-moore.com>
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121ab822 |
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13-Jul-2016 |
Vivek Goyal <vgoyal@redhat.com> |
security,overlayfs: Provide security hook for copy up of xattrs for overlay file Provide a security hook which is called when xattrs of a file are being copied up. This hook is called once for each xattr and LSM can return 0 if the security module wants the xattr to be copied up, 1 if the security module wants the xattr to be discarded on the copy, -EOPNOTSUPP if the security module does not handle/manage the xattr, or a -errno upon an error. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespace cleanup for checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
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d8ad8b49 |
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13-Jul-2016 |
Vivek Goyal <vgoyal@redhat.com> |
security, overlayfs: provide copy up security hook for unioned files Provide a security hook to label new file correctly when a file is copied up from lower layer to upper layer of a overlay/union mount. This hook can prepare a new set of creds which are suitable for new file creation during copy up. Caller will use new creds to create file and then revert back to old creds and release new creds. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespace cleanup to appease checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
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4f3ccd76 |
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20-Jul-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
qstr: constify dentry_init_security Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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457db29b |
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08-Apr-2016 |
Baolin Wang <baolin.wang@linaro.org> |
security: Introduce security_settime64() security_settime() uses a timespec, which is not year 2038 safe on 32bit systems. Thus this patch introduces the security_settime64() function with timespec64 type. We also convert the cap_settime() helper function to use the 64bit types. This patch then moves security_settime() to the header file as an inline helper function so that existing users can be iteratively converted. None of the existing hooks is using the timespec argument and therefor the patch is not making any functional changes. Cc: Serge Hallyn <serge.hallyn@canonical.com>, Cc: James Morris <james.l.morris@oracle.com>, Cc: "Serge E. Hallyn" <serge@hallyn.com>, Cc: Paul Moore <pmoore@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Kees Cook <keescook@chromium.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Reviewed-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> [jstultz: Reworded commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
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9b091556 |
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20-Apr-2016 |
Kees Cook <keescook@chromium.org> |
LSM: LoadPin for kernel file loading restrictions This LSM enforces that kernel-loaded files (modules, firmware, etc) must all come from the same filesystem, with the expectation that such a filesystem is backed by a read-only device such as dm-verity or CDROM. This allows systems that have a verified and/or unchangeable filesystem to enforce module and firmware loading restrictions without needing to sign the files individually. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
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3c9d6296 |
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07-Apr-2016 |
Paolo Abeni <pabeni@redhat.com> |
security: drop the unused hook skb_owned_by The skb_owned_by hook was added with the commit ca10b9e9a8ca ("selinux: add a skb_owned_by() hook") and later removed when said commit was reverted. Later on, when switching to list of hooks, a field named 'skb_owned_by' was included into the security_hook_head struct, but without any users nor caller. This commit removes the said left-over field. Fixes: b1d9e6b0646d ("LSM: Switch to lists of hooks") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Paul Moore <pmoore@paul-moore.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
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3b73b68c |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_sb_pivotroot() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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77b286c0 |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_path_chroot() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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3ccee46a |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_path_{link,rename} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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d3607752 |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_path_{mkdir,mknod,symlink} ... as well as unix_mknod() and may_o_create() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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989f74e0 |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_path_{unlink,rmdir} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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be01f9f2 |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify chmod_common/security_path_chmod Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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8a04c43b |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_sb_mount() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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7fd25dac |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify chown_common/security_path_chown Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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81f4c506 |
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25-Mar-2016 |
Al Viro <viro@zeniv.linux.org.uk> |
constify security_path_truncate() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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a1db7420 |
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30-Dec-2015 |
Mimi Zohar <zohar@linux.vnet.ibm.com> |
module: replace copy_module_from_fd with kernel version Replace copy_module_from_fd() with kernel_read_file_from_fd(). Although none of the upstreamed LSMs define a kernel_module_from_file hook, IMA is called, based on policy, to prevent unsigned kernel modules from being loaded by the original kernel module syscall and to measure/appraise signed kernel modules. The security function security_kernel_module_from_file() was called prior to reading a kernel module. Preventing unsigned kernel modules from being loaded by the original kernel module syscall remains on the pre-read kernel_read_file() security hook. Instead of reading the kernel module twice, once for measuring/appraising and again for loading the kernel module, the signature validation is moved to the kernel_post_read_file() security hook. This patch removes the security_kernel_module_from_file() hook and security call. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
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39eeb4fb |
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30-Jan-2016 |
Mimi Zohar <zohar@linux.vnet.ibm.com> |
security: define kernel_read_file hook The kernel_read_file security hook is called prior to reading the file into memory. Changelog v4+: - export security_kernel_read_file() Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
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e40ba6d5 |
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18-Nov-2015 |
Mimi Zohar <zohar@linux.vnet.ibm.com> |
firmware: replace call to fw_read_file_contents() with kernel version Replace the fw_read_file_contents with kernel_file_read_from_path(). Although none of the upstreamed LSMs define a kernel_fw_from_file hook, IMA is called by the security function to prevent unsigned firmware from being loaded and to measure/appraise signed firmware, based on policy. Instead of reading the firmware twice, once for measuring/appraising the firmware and again for reading the firmware contents into memory, the kernel_post_read_file() security hook calculates the file hash based on the in memory file buffer. The firmware is read once. This patch removes the LSM kernel_fw_from_file() hook and security call. Changelog v4+: - revert dropped buf->size assignment - reported by Sergey Senozhatsky v3: - remove kernel_fw_from_file hook - use kernel_file_read_from_path() - requested by Luis v2: - reordered and squashed firmware patches - fix MAX firmware size (Kees Cook) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
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bc8ca5b9 |
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24-Jan-2016 |
Mimi Zohar <zohar@linux.vnet.ibm.com> |
vfs: define kernel_read_file_id enumeration To differentiate between the kernel_read_file() callers, this patch defines a new enumeration named kernel_read_file_id and includes the caller identifier as an argument. Subsequent patches define READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS, READING_FIRMWARE, READING_MODULE, and READING_POLICY. Changelog v3: - Replace the IMA specific enumeration with a generic one. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk>
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b44a7dfc |
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28-Dec-2015 |
Mimi Zohar <zohar@linux.vnet.ibm.com> |
vfs: define a generic function to read a file from the kernel For a while it was looked down upon to directly read files from Linux. These days there exists a few mechanisms in the kernel that do just this though to load a file into a local buffer. There are minor but important checks differences on each. This patch set is the first attempt at resolving some of these differences. This patch introduces a common function for reading files from the kernel with the corresponding security post-read hook and function. Changelog v4+: - export security_kernel_post_read_file() - Fengguang Wu v3: - additional bounds checking - Luis v2: - To simplify patch review, re-ordered patches Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk>
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#
6f3be9f5 |
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24-Dec-2015 |
Andreas Gruenbacher <agruenba@redhat.com> |
security: Add hook to invalidate inode security labels Add a hook to invalidate an inode's security label when the cached information becomes invalid. Add the new hook in selinux: set a flag when a security label becomes invalid. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
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d6335d77 |
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24-Dec-2015 |
Andreas Gruenbacher <agruenba@redhat.com> |
security: Make inode argument of inode_getsecid non-const Make the inode argument of the inode_getsecid hook non-const so that we can use it to revalidate invalid security labels. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
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ea861dfd |
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24-Dec-2015 |
Andreas Gruenbacher <agruenba@redhat.com> |
security: Make inode argument of inode_getsecurity non-const Make the inode argument of the inode_getsecurity hook non-const so that we can use it to revalidate invalid security labels. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>
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#
730daa16 |
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23-Jul-2015 |
Kees Cook <keescook@chromium.org> |
Yama: remove needless CONFIG_SECURITY_YAMA_STACKED Now that minor LSMs can cleanly stack with major LSMs, remove the unneeded config for Yama to be made to explicitly stack. Just selecting the main Yama CONFIG will allow it to work, regardless of the major LSM. Since distros using Yama are already forcing it to stack, this is effectively a no-op change. Additionally add MAINTAINERS entry. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
b1d9e6b0 |
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02-May-2015 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Switch to lists of hooks Instead of using a vector of security operations with explicit, special case stacking of the capability and yama hooks use lists of hooks with capability and yama hooks included as appropriate. The security_operations structure is no longer required. Instead, there is a union of the function pointers that allows all the hooks lists to use a common mechanism for list management while retaining typing. Each module supplies an array describing the hooks it provides instead of a sparsely populated security_operations structure. The description includes the element that gets put on the hook list, avoiding the issues surrounding individual element allocation. The method for registering security modules is changed to reflect the information available. The method for removing a module, currently only used by SELinux, has also changed. It should be generic now, however if there are potential race conditions based on ordering of hook removal that needs to be addressed by the calling module. The security hooks are called from the lists and the first failure is returned. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
e20b043a |
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02-May-2015 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Add security module hook list heads Add a list header for each security hook. They aren't used until later in the patch series. They are grouped together in a structure so that there doesn't need to be an external address for each. Macro-ize the initialization of the security_operations for each security module in anticipation of changing out the security_operations structure. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
fe7bb272 |
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02-May-2015 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Add the comment to lsm_hooks.h Add the large comment describing the content of the security_operations structure to lsm_hooks.h. This wasn't done in the previous (1/7) patch because it would have exceeded the mail list size limits. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
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#
3c4ed7bd |
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02-May-2015 |
Casey Schaufler <casey@schaufler-ca.com> |
LSM: Split security.h The security.h header file serves two purposes, interfaces for users of the security modules and interfaces for security modules. Users of the security modules don't need to know about what's in the security_operations structure, so pull it out into it's own header, lsm_hooks.h Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <james.l.morris@oracle.com>
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