apparmor: add io_uring mediation

For now, the io_uring mediation is limited to sqpoll and
override_creds.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: add user namespace creation mediation

Unprivileged user namespace creation is often used as a first step
in privilege escalation attacks. Instead of disabling it at the
sysrq level, which blocks its legitimate use as for setting up a sandbox,
allow control on a per domain basis.

This allows an admin to quickly lock down a system while also still
allowing legitimate use.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: pass cred through to audit info.

The cred is needed to properly audit some messages, and will be needed
in the future for uid conditional mediation. So pass it through to
where the apparmor_audit_data struct gets defined.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: rename audit_data->label to audit_data->subj_label

rename audit_data's label field to subj_label to better reflect its
use. Also at the same time drop unneeded assignments to ->subj_label
as the later call to aa_check_perms will do the assignment if needed.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: combine common_audit_data and apparmor_audit_data

Everywhere where common_audit_data is used apparmor audit_data is also
used. We can simplify the code and drop the use of the aad macro
everywhere by combining the two structures.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: add mediation class information to auditing

Audit messages currently don't contain the mediation class which can
make them less clear than they should be in some circumstances. With
newer mediation classes coming this potential confusion will become
worse.

Fix this by adding the mediatin class to the messages.

Signed-off-by: John Johansen <john.johansen@canonical.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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>

apparmor: Add support for audit rule filtering

This patch adds support to Apparmor for integrating with audit rule
filtering. Right now it only handles SUBJ_ROLE, interpreting it as a
single component of a label. This is sufficient to get Apparmor working
with IMA's appraisal rules without any modifications on the IMA side.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: add base infastructure for socket mediation

version 2 - Force an abi break. Network mediation will only be
available in v8 abi complaint policy.

Provide a basic mediation of sockets. This is not a full net mediation
but just whether a spcific family of socket can be used by an
application, along with setting up some basic infrastructure for
network mediation to follow.

the user space rule hav the basic form of
NETWORK RULE = [ QUALIFIERS ] 'network' [ DOMAIN ]
[ TYPE | PROTOCOL ]

DOMAIN = ( 'inet' | 'ax25' | 'ipx' | 'appletalk' | 'netrom' |
'bridge' | 'atmpvc' | 'x25' | 'inet6' | 'rose' |
'netbeui' | 'security' | 'key' | 'packet' | 'ash' |
'econet' | 'atmsvc' | 'sna' | 'irda' | 'pppox' |
'wanpipe' | 'bluetooth' | 'netlink' | 'unix' | 'rds' |
'llc' | 'can' | 'tipc' | 'iucv' | 'rxrpc' | 'isdn' |
'phonet' | 'ieee802154' | 'caif' | 'alg' | 'nfc' |
'vsock' | 'mpls' | 'ib' | 'kcm' ) ','

TYPE = ( 'stream' | 'dgram' | 'seqpacket' | 'rdm' | 'raw' |
'packet' )

PROTOCOL = ( 'tcp' | 'udp' | 'icmp' )

eg.
network,
network inet,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

apparmor: audit unknown signal numbers

Allow apparmor to audit the number of a signal that it does not
provide a mapping for and is currently being reported only as
unknown.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: fix resource audit messages when auditing peer

Resource auditing is using the peer field which is not available
when the rlim data struct is used, because it is a different element
of the same union. Accessing peer during resource auditing could
cause garbage log entries or even oops the kernel.

Move the rlim data block into the same struct as the peer field
so they can be used together.

CC: <stable@vger.kernel.org>
Fixes: 86b92cb782b3 ("apparmor: move resource checks to using labels")
Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: fix oops in audit_signal_cb hook

The apparmor_audit_data struct ordering got messed up during a merge
conflict, resulting in the signal integer and peer pointer being in
a union instead of a struct.

For most of the 4.13 and 4.14 life cycle, this was hidden by
commit 651e28c5537a ("apparmor: add base infastructure for socket
mediation") which fixed the apparmor_audit_data struct when its data
was added. When that commit was reverted in -rc7 the signal audit bug
was exposed, and unfortunately it never showed up in any of the
testing until after 4.14 was released. Shaun Khan, Zephaniah
E. Loss-Cutler-Hull filed nearly simultaneous bug reports (with
different oopes, the smaller of which is included below).

Full credit goes to Tetsuo Handa for jumping on this as well and
noticing the audit data struct problem and reporting it.

[ 76.178568] BUG: unable to handle kernel paging request at
ffffffff0eee3bc0
[ 76.178579] IP: audit_signal_cb+0x6c/0xe0
[ 76.178581] PGD 1a640a067 P4D 1a640a067 PUD 0
[ 76.178586] Oops: 0000 [#1] PREEMPT SMP
[ 76.178589] Modules linked in: fuse rfcomm bnep usblp uvcvideo btusb
btrtl btbcm btintel bluetooth ecdh_generic ip6table_filter ip6_tables
xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack
iptable_filter ip_tables x_tables intel_rapl joydev wmi_bmof serio_raw
iwldvm iwlwifi shpchp kvm_intel kvm irqbypass autofs4 algif_skcipher
nls_iso8859_1 nls_cp437 crc32_pclmul ghash_clmulni_intel
[ 76.178620] CPU: 0 PID: 10675 Comm: pidgin Not tainted
4.14.0-f1-dirty #135
[ 76.178623] Hardware name: Hewlett-Packard HP EliteBook Folio
9470m/18DF, BIOS 68IBD Ver. F.62 10/22/2015
[ 76.178625] task: ffff9c7a94c31dc0 task.stack: ffffa09b02a4c000
[ 76.178628] RIP: 0010:audit_signal_cb+0x6c/0xe0
[ 76.178631] RSP: 0018:ffffa09b02a4fc08 EFLAGS: 00010292
[ 76.178634] RAX: ffffa09b02a4fd60 RBX: ffff9c7aee0741f8 RCX:
0000000000000000
[ 76.178636] RDX: ffffffffee012290 RSI: 0000000000000006 RDI:
ffff9c7a9493d800
[ 76.178638] RBP: ffffa09b02a4fd40 R08: 000000000000004d R09:
ffffa09b02a4fc46
[ 76.178641] R10: ffffa09b02a4fcb8 R11: ffff9c7ab44f5072 R12:
ffffa09b02a4fd40
[ 76.178643] R13: ffffffff9e447be0 R14: ffff9c7a94c31dc0 R15:
0000000000000001
[ 76.178646] FS: 00007f8b11ba2a80(0000) GS:ffff9c7afea00000(0000)
knlGS:0000000000000000
[ 76.178648] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 76.178650] CR2: ffffffff0eee3bc0 CR3: 00000003d5209002 CR4:
00000000001606f0
[ 76.178652] Call Trace:
[ 76.178660] common_lsm_audit+0x1da/0x780
[ 76.178665] ? d_absolute_path+0x60/0x90
[ 76.178669] ? aa_check_perms+0xcd/0xe0
[ 76.178672] aa_check_perms+0xcd/0xe0
[ 76.178675] profile_signal_perm.part.0+0x90/0xa0
[ 76.178679] aa_may_signal+0x16e/0x1b0
[ 76.178686] apparmor_task_kill+0x51/0x120
[ 76.178690] security_task_kill+0x44/0x60
[ 76.178695] group_send_sig_info+0x25/0x60
[ 76.178699] kill_pid_info+0x36/0x60
[ 76.178703] SYSC_kill+0xdb/0x180
[ 76.178707] ? preempt_count_sub+0x92/0xd0
[ 76.178712] ? _raw_write_unlock_irq+0x13/0x30
[ 76.178716] ? task_work_run+0x6a/0x90
[ 76.178720] ? exit_to_usermode_loop+0x80/0xa0
[ 76.178723] entry_SYSCALL_64_fastpath+0x13/0x94
[ 76.178727] RIP: 0033:0x7f8b0e58b767
[ 76.178729] RSP: 002b:00007fff19efd4d8 EFLAGS: 00000206 ORIG_RAX:
000000000000003e
[ 76.178732] RAX: ffffffffffffffda RBX: 0000557f3e3c2050 RCX:
00007f8b0e58b767
[ 76.178735] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
000000000000263b
[ 76.178737] RBP: 0000000000000000 R08: 0000557f3e3c2270 R09:
0000000000000001
[ 76.178739] R10: 000000000000022d R11: 0000000000000206 R12:
0000000000000000
[ 76.178741] R13: 0000000000000001 R14: 0000557f3e3c13c0 R15:
0000000000000000
[ 76.178745] Code: 48 8b 55 18 48 89 df 41 b8 20 00 08 01 5b 5d 48 8b
42 10 48 8b 52 30 48 63 48 4c 48 8b 44 c8 48 31 c9 48 8b 70 38 e9 f4 fd
00 00 <48> 8b 14 d5 40 27 e5 9e 48 c7 c6 7d 07 19 9f 48 89 df e8 fd 35
[ 76.178794] RIP: audit_signal_cb+0x6c/0xe0 RSP: ffffa09b02a4fc08
[ 76.178796] CR2: ffffffff0eee3bc0
[ 76.178799] ---[ end trace 514af9529297f1a3 ]---

Fixes: cd1dbf76b23d ("apparmor: add the ability to mediate signals")
Reported-by: Zephaniah E. Loss-Cutler-Hull <warp-spam_kernel@aehallh.com>
Reported-by: Shuah Khan <shuahkh@osg.samsung.com>
Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Tested-by: Ivan Kozik <ivan@ludios.org>
Tested-by: Zephaniah E. Loss-Cutler-Hull <warp-spam_kernel@aehallh.com>
Tested-by: Christian Boltz <apparmor@cboltz.de>
Tested-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>

Revert "apparmor: add base infastructure for socket mediation"

This reverts commit 651e28c5537abb39076d3949fb7618536f1d242e.

This caused a regression:
"The specific problem is that dnsmasq refuses to start on openSUSE Leap
42.2. The specific cause is that and attempt to open a PF_LOCAL socket
gets EACCES. This means that networking doesn't function on a system
with a 4.14-rc2 system."

Sadly, the developers involved seemed to be in denial for several weeks
about this, delaying the revert. This has not been a good release for
the security subsystem, and this area needs to change development
practices.

Reported-and-bisected-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Tracked-by: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Seth Arnold <seth.arnold@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

apparmor: add base infastructure for socket mediation

Provide a basic mediation of sockets. This is not a full net mediation
but just whether a spcific family of socket can be used by an
application, along with setting up some basic infrastructure for
network mediation to follow.

the user space rule hav the basic form of
NETWORK RULE = [ QUALIFIERS ] 'network' [ DOMAIN ]
[ TYPE | PROTOCOL ]

DOMAIN = ( 'inet' | 'ax25' | 'ipx' | 'appletalk' | 'netrom' |
'bridge' | 'atmpvc' | 'x25' | 'inet6' | 'rose' |
'netbeui' | 'security' | 'key' | 'packet' | 'ash' |
'econet' | 'atmsvc' | 'sna' | 'irda' | 'pppox' |
'wanpipe' | 'bluetooth' | 'netlink' | 'unix' | 'rds' |
'llc' | 'can' | 'tipc' | 'iucv' | 'rxrpc' | 'isdn' |
'phonet' | 'ieee802154' | 'caif' | 'alg' | 'nfc' |
'vsock' | 'mpls' | 'ib' | 'kcm' ) ','

TYPE = ( 'stream' | 'dgram' | 'seqpacket' | 'rdm' | 'raw' |
'packet' )

PROTOCOL = ( 'tcp' | 'udp' | 'icmp' )

eg.
network,
network inet,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

apparmor: make policy_unpack able to audit different info messages

Switch unpack auditing to using the generic name field in the audit
struct and make it so we can start adding new info messages about
why an unpack failed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

apparmor: add mount mediation

Add basic mount mediation. That allows controlling based on basic
mount parameters. It does not include special mount parameters for
apparmor, super block labeling, or any triggers for apparmor namespace
parameter modifications on pivot root.

default userspace policy rules have the form of
MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT )

MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ]
[ '->' MOUNTPOINT FILEGLOB ]

REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ]
MOUNTPOINT FILEGLOB

UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB

MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' )
MOUNT FSTYPE EXPRESSION ]
[ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ]

MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION )

MOUNT FSTYPE LIST = Comma separated list of valid filesystem and
virtual filesystem types (eg ext4, debugfs, etc)

MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION )

MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS.

MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' |
'noexec' | 'exec' | 'sync' | 'async' | 'remount' |
'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' |
'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' |
'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' |
'unbindable' | 'runbindable' | 'private' | 'rprivate' |
'slave' | 'rslave' | 'shared' | 'rshared' |
'relatime' | 'norelatime' | 'iversion' | 'noiversion' |
'strictatime' | 'nouser' | 'user' )

MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ...

PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ]
[ NEW ROOT FILEGLOB ]

SOURCE FILEGLOB = FILEGLOB

MOUNTPOINT FILEGLOB = FILEGLOB

eg.
mount,
mount /dev/foo,
mount options=ro /dev/foo -> /mnt/,
mount options in (ro,atime) /dev/foo -> /mnt/,
mount options=ro options=atime,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

apparmor: add the ability to mediate signals

Add signal mediation where the signal can be mediated based on the
signal, direction, or the label or the peer/target. The signal perms
are verified on a cross check to ensure policy consistency in the case
of incremental policy load/replacement.

The optimization of skipping the cross check when policy is guaranteed
to be consistent (single compile unit) remains to be done.

policy rules have the form of
SIGNAL_RULE = [ QUALIFIERS ] 'signal' [ SIGNAL ACCESS PERMISSIONS ]
[ SIGNAL SET ] [ SIGNAL PEER ]

SIGNAL ACCESS PERMISSIONS = SIGNAL ACCESS | SIGNAL ACCESS LIST

SIGNAL ACCESS LIST = '(' Comma or space separated list of SIGNAL
ACCESS ')'

SIGNAL ACCESS = ( 'r' | 'w' | 'rw' | 'read' | 'write' | 'send' |
'receive' )

SIGNAL SET = 'set' '=' '(' SIGNAL LIST ')'

SIGNAL LIST = Comma or space separated list of SIGNALS

SIGNALS = ( 'hup' | 'int' | 'quit' | 'ill' | 'trap' | 'abrt' |
'bus' | 'fpe' | 'kill' | 'usr1' | 'segv' | 'usr2' |
'pipe' | 'alrm' | 'term' | 'stkflt' | 'chld' | 'cont' |
'stop' | 'stp' | 'ttin' | 'ttou' | 'urg' | 'xcpu' |
'xfsz' | 'vtalrm' | 'prof' | 'winch' | 'io' | 'pwr' |
'sys' | 'emt' | 'exists' | 'rtmin+0' ... 'rtmin+32'
)

SIGNAL PEER = 'peer' '=' AARE

eg.
signal, # allow all signals
signal send set=(hup, kill) peer=foo,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

apparmor: add domain label stacking info to apparmorfs

Now that the domain label transition is complete advertise it to
userspace.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: mediate files when they are received

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: switch from profiles to using labels on contexts

Begin the actual switch to using domain labels by storing them on
the context and converting the label to a singular profile where
possible.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: revalidate files during exec

Instead of running file revalidation lazily when read/write are called
copy selinux and revalidate the file table on exec. This avoids
extra mediation overhead in read/write and also prevents file handles
being passed through to a grand child unchecked.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: add gerneric permissions struct and support fns

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: change aad apparmor_audit_data macro to a fn macro

The aad macro can replace aad strings when it is not intended to. Switch
to a fn macro so it is only applied when intended.

Also at the same time cleanup audit_data initialization by putting
common boiler plate behind a macro, and dropping the gfp_t parameter
which will become useless.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: change op from int to const char *

Having ops be an integer that is an index into an op name table is
awkward and brittle. Every op change requires an edit for both the
op constant and a string in the table. Instead switch to using const
strings directly, eliminating the need for the table that needs to
be kept in sync.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: add ns name to the audit data for policy loads

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: remove parent task info from audit logging

The reporting of the parent task info is a vestage from old versions of
apparmor. The need for this information was removed by unique null-
profiles before apparmor was upstreamed so remove this info from logging.

Signed-off-by: John Johansen <john.johansen@canonical.com>

apparmor: add interface files for profiles and namespaces

Add basic interface files to access namespace and profile information.
The interface files are created when a profile is loaded and removed
when the profile or namespace is removed.

Signed-off-by: John Johansen <john.johansen@canonical.com>

userns: Convert apparmor to use kuid and kgid where appropriate

Cc: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

apparmor: move task from common_audit_data to apparmor_audit_data

apparmor is the only LSM that uses the common_audit_data tsk field.
Instead of making all LSMs pay for the stack space move the aa usage into
the apparmor_audit_data.

Signed-off-by: Eric Paris <eparis@redhat.com>

LSM: shrink sizeof LSM specific portion of common_audit_data

Linus found that the gigantic size of the common audit data caused a big
perf hit on something as simple as running stat() in a loop. This patch
requires LSMs to declare the LSM specific portion separately rather than
doing it in a union. Thus each LSM can be responsible for shrinking their
portion and don't have to pay a penalty just because other LSMs have a
bigger space requirement.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

AppArmor: add const qualifiers to string arrays

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>

AppArmor: Fix dropping of allowed operations that are force audited

The audit permission flag, that specifies an audit message should be
provided when an operation is allowed, was being ignored in some cases.

This is because the auto audit mode (which determines the audit mode from
system flags) was incorrectly assigned the same value as audit mode. The
shared value would result in messages that should be audited going through
a second evaluation as to whether they should be audited based on the
auto audit, resulting in some messages being dropped.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>

AppArmor: basic auditing infrastructure.

Update lsm_audit for AppArmor specific data, and add the core routines for
AppArmor uses for auditing.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>