cifs: Add tracing for the cifs_tcon struct refcounting

Add tracing for the refcounting/lifecycle of the cifs_tcon struct, marking
different events with different labels and giving each tcon its own debug
ID so that the tracelines corresponding to individual tcons can be
distinguished. This can be enabled with:

echo 1 >/sys/kernel/debug/tracing/events/cifs/smb3_tcon_ref/enable

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: instantiate when creating SFU files

In cifs_sfu_make_node(), on success, instantiate rather than leave it
with dentry unhashed negative to support callers that expect mknod(2)
to always instantiate.

This fixes the following test case:

mount.cifs //srv/share /mnt -o ...,sfu
mkfifo /mnt/fifo
./xfstests/ltp/growfiles -b -W test -e 1 -u -i 0 -L 30 /mnt/fifo
...
BUG: unable to handle page fault for address: 000000034cec4e58
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 1 PREEMPT SMP PTI
CPU: 0 PID: 138098 Comm: growfiles Kdump: loaded Not tainted
5.14.0-436.3987_1240945149.el9.x86_64 #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:_raw_callee_save__kvm_vcpu_is_preempted+0x0/0x20
Code: e8 15 d9 61 00 e9 63 ff ff ff 41 bd ea ff ff ff e9 58 ff ff ff e8
d0 71 c0 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 04
fd 60 2b c1 99 80 b8 90 50 03 00 00 0f 95 c0 c3 cc cc cc
RSP: 0018:ffffb6a143cf7cf8 EFLAGS: 00010206
RAX: ffff8a9bc30fb038 RBX: ffff8a9bc666a200 RCX: ffff8a9cc0260000
RDX: 00000000736f622e RSI: ffff8a9bc30fb038 RDI: 000000007665645f
RBP: ffffb6a143cf7d70 R08: 0000000000001000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8a9bc666a200
R13: 0000559a302a12b0 R14: 0000000000001000 R15: 0000000000000000
FS: 00007fbed1dbb740(0000) GS:ffff8a9cf0000000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000034cec4e58 CR3: 0000000128ec6006 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
? show_trace_log_lvl+0x1c4/0x2df
? show_trace_log_lvl+0x1c4/0x2df
? __mutex_lock.constprop.0+0x5f7/0x6a0
? __die_body.cold+0x8/0xd
? page_fault_oops+0x134/0x170
? exc_page_fault+0x62/0x150
? asm_exc_page_fault+0x22/0x30
? _pfx_raw_callee_save__kvm_vcpu_is_preempted+0x10/0x10
__mutex_lock.constprop.0+0x5f7/0x6a0
? __mod_memcg_lruvec_state+0x84/0xd0
pipe_write+0x47/0x650
? do_anonymous_page+0x258/0x410
? inode_security+0x22/0x60
? selinux_file_permission+0x108/0x150
vfs_write+0x2cb/0x410
ksys_write+0x5f/0xe0
do_syscall_64+0x5c/0xf0
? syscall_exit_to_user_mode+0x22/0x40
? do_syscall_64+0x6b/0xf0
? sched_clock_cpu+0x9/0xc0
? exc_page_fault+0x62/0x150
entry_SYSCALL_64_after_hwframe+0x6e/0x76

Cc: stable@vger.kernel.org
Fixes: 72bc63f5e23a ("smb3: fix creating FIFOs when mounting with "sfu" mount option")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix potential UAF in smb2_is_network_name_deleted()

Skip sessions that are being teared down (status == SES_EXITING) to
avoid UAF.

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb3: retrying on failed server close

In the current implementation, CIFS close sends a close to the
server and does not check for the success of the server close.
This patch adds functionality to check for server close return
status and retries in case of an EBUSY or EAGAIN error.

This can help avoid handle leaks

Cc: stable@vger.kernel.org
Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: replace deprecated strncpy with strscpy

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

In cifssmb.c:
Using strncpy with a length argument equal to strlen(src) is generally
dangerous because it can cause string buffers to not be NUL-terminated.
In this case, however, there was extra effort made to ensure the buffer
was NUL-terminated via a manual NUL-byte assignment. In an effort to rid
the kernel of strncpy() use, let's swap over to using strscpy() which
guarantees NUL-termination on the destination buffer.

To handle the case where ea_name is NULL, let's use the ?: operator to
substitute in an empty string, thereby allowing strscpy to still
NUL-terminate the destintation string.

Interesting note: this flex array buffer may go on to also have some
value encoded after the NUL-termination:
| if (ea_value_len)
| memcpy(parm_data->list.name + name_len + 1,
| ea_value, ea_value_len);

Now for smb2ops.c and smb2transport.c:
Both of these cases are simple, strncpy() is used to copy string
literals which have a length less than the destination buffer's size. We
can simply swap in the new 2-argument version of strscpy() introduced in
Commit e6584c3964f2f ("string: Allow 2-argument strscpy()").

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: make sure server interfaces are requested only for SMB3+

Some code paths for querying server interfaces make a false
assumption that it will only get called for SMB3+. Since this
function now can get called from a generic code paths, the correct
thing to do is to have specific handler for this functionality
per SMB dialect, and call this handler.

This change adds such a handler and implements this handler only
for SMB 3.0 and 3.1.1.

Cc: stable@vger.kernel.org
Cc: Jan Čermák <sairon@sairon.cz>
Reported-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: add support for WSL reparse points

Add support for creating special files via WSL reparse points when
using 'reparse=wsl' mount option. They're faster than NFS reparse
points because they don't require extra roundtrips to figure out what
->d_type a specific dirent is as such information is already stored in
query dir responses and then making getdents() calls faster.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: move most of reparse point handling code to common file

In preparation to add support for creating special files also via WSL
reparse points in next commits.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: handle path separator of created SMB symlinks

Convert path separator to CIFS_DIR_SEP(cifs_sb) from symlink target
before sending it over the wire otherwise the created SMB symlink may
become innaccesible from server side.

Fixes: 514d793e27a3 ("smb: client: allow creating symlinks via reparse points")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: update the same create_guid on replay

File open requests made to the server contain a
CreateGuid, which is used by the server to identify
the open request. If the same request needs to be
replayed, it needs to be sent with the same CreateGuid
in the durable handle v2 context.

Without doing so, we could end up leaking handles on
the server when:
1. multichannel is used AND
2. connection goes down, but not for all channels

This is because the replayed open request would have a
new CreateGuid and the server will treat this as a new
request and open a new handle.

This change fixes this by reusing the existing create_guid
stored in the cached fid struct.

REF: MS-SMB2 4.9 Replay Create Request on an Alternate Channel

Fixes: 4f1fffa23769 ("cifs: commands that are retried should have replay flag set")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: fix underflow in parse_server_interfaces()

In this loop, we step through the buffer and after each item we check
if the size_left is greater than the minimum size we need. However,
the problem is that "bytes_left" is type ssize_t while sizeof() is type
size_t. That means that because of type promotion, the comparison is
done as an unsigned and if we have negative bytes left the loop
continues instead of ending.

Fixes: fe856be475f7 ("CIFS: parse and store info on iface queries")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: commands that are retried should have replay flag set

MS-SMB2 states that the header flag SMB2_FLAGS_REPLAY_OPERATION
needs to be set when a command needs to be retried, so that
the server is aware that this is a replay for an operation that
appeared before.

This can be very important, for example, for state changing
operations and opens which get retried following a reconnect;
since the client maybe unaware of the status of the previous
open.

This is particularly important for multichannel scenario, since
disconnection of one connection does not mean that the session
is lost. The requests can be replayed on another channel.

This change also makes use of exponential back-off before replays
and also limits the number of retries to "retrans" mount option
value.

Also, this change does not modify the read/write codepath.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: Share server EOF pos with netfslib

Use cifsi->netfs_ctx.remote_i_size instead of cifsi->server_eof so that
netfslib can refer to it to.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: update iface_last_update on each query-and-update

iface_last_update was an unused field when it was introduced.
Later, when we had periodic update of server interface list,
this field was used regularly to decide when to update next.

However, with the new logic of updating the interfaces, it
becomes crucial that this field be updated whenever
parse_server_interfaces runs successfully.

This change updates this field when either the server does
not support query of interfaces; so that we do not query
the interfaces repeatedly. It also updates the field when
the function reaches the end.

Fixes: aa45dadd34e4 ("cifs: change iface_list from array to sorted linked list")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: handle servers that still advertise multichannel after disabling

Some servers like Azure SMB servers always advertise multichannel
capability in server capabilities list. Such servers return error
STATUS_NOT_IMPLEMENTED for ioctl calls to query server interfaces,
and expect clients to consider that as a sign that they do not support
multichannel.

We already handled this at mount time. Soon after the tree connect,
we query server interfaces. And when server returned STATUS_NOT_IMPLEMENTED,
we kept interface list as empty. When cifs_try_adding_channels gets
called, it would not find any interfaces, so will not add channels.

For the case where an active multichannel mount exists, and multichannel
is disabled by such a server, this change will now allow the client
to disable secondary channels on the mount. It will check the return
status of query server interfaces call soon after a tree reconnect.
If the return status is EOPNOTSUPP, then instead of the check to add
more channels, we'll disable the secondary channels instead.

For better code reuse, this change also moves the common code for
disabling multichannel to a helper function.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: get rid of dup length check in parse_reparse_point()

smb2_compound_op(SMB2_OP_GET_REPARSE) already checks if ioctl response
has a valid reparse data buffer's length, so there's no need to check
it again in parse_reparse_point().

In order to get rid of duplicate check, validate reparse data buffer's
length also in cifs_query_reparse_point().

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: Pass unbyteswapped eof value into SMB2_set_eof()

Change SMB2_set_eof() to take eof as CPU order rather than __le64 and pass
it directly rather than by pointer. This moves the conversion down into
SMB_set_eof() rather than all of its callers and means we don't need to
undo it for the traceline.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: cleanup smb2_query_reparse_point()

Use smb2_compound_op() with SMB2_OP_GET_REPARSE to get reparse point.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: allow creating symlinks via reparse points

Add support for creating symlinks via IO_REPARSE_TAG_SYMLINK reparse
points in SMB2+.

These are fully supported by most SMB servers and documented in
MS-FSCC. Also have the advantage of requiring fewer roundtrips as
their symlink targets can be parsed directly from CREATE responses on
STATUS_STOPPED_ON_SYMLINK errors.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311260838.nx5mkj1j-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: allow creating special files via reparse points

Add support for creating special files (e.g. char/block devices,
sockets, fifos) via NFS reparse points on SMB2+, which are fully
supported by most SMB servers and documented in MS-FSCC.

smb2_get_reparse_inode() creates the file with a corresponding reparse
point buffer set in @iov through a single roundtrip to the server.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311260746.HOJ039BV-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: do not depend on release_iface for maintaining iface_list

parse_server_interfaces should be in complete charge of maintaining
the iface_list linked list. Today, iface entries are removed
from the list only when the last refcount is dropped.
i.e. in release_iface. However, this can result in undercounting
of refcount if the server stops advertising interfaces (which
Azure SMB server does).

This change puts parse_server_interfaces in full charge of
maintaining the iface_list. So if an empty list is returned
by the server, the entries in the list will immediately be
removed. This way, a following call to the same function will
not find entries in the list.

Fixes: aa45dadd34e4 ("cifs: change iface_list from array to sorted linked list")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: cifs_chan_is_iface_active should be called with chan_lock held

cifs_chan_is_iface_active checks the channels of a session to see
if the associated iface is active. This should always happen
with chan_lock held. However, these two callers of this function
were missing this locking.

This change makes sure the function calls are protected with
proper locking.

Fixes: b54034a73baf ("cifs: during reconnect, update interface if necessary")
Fixes: fa1d0508bdd4 ("cifs: account for primary channel in the interface list")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix potential OOB in smb2_dump_detail()

Validate SMB message with ->check_message() before calling
->calc_smb_size().

This fixes CVE-2023-6610.

Reported-by: j51569436@gmail.com
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218219
Cc; stable@vger.kernel.org
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix OOB in cifsd when receiving compounded resps

Validate next header's offset in ->next_header() so that it isn't
smaller than MID_HEADER_SIZE(server) and then standard_receive3() or
->receive() ends up writing off the end of the buffer because
'pdu_length - MID_HEADER_SIZE(server)' wraps up to a huge length:

BUG: KASAN: slab-out-of-bounds in _copy_to_iter+0x4fc/0x840
Write of size 701 at addr ffff88800caf407f by task cifsd/1090

CPU: 0 PID: 1090 Comm: cifsd Not tainted 6.7.0-rc4 #5
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x4a/0x80
print_report+0xcf/0x650
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __phys_addr+0x46/0x90
kasan_report+0xd8/0x110
? _copy_to_iter+0x4fc/0x840
? _copy_to_iter+0x4fc/0x840
kasan_check_range+0x105/0x1b0
__asan_memcpy+0x3c/0x60
_copy_to_iter+0x4fc/0x840
? srso_alias_return_thunk+0x5/0xfbef5
? hlock_class+0x32/0xc0
? srso_alias_return_thunk+0x5/0xfbef5
? __pfx__copy_to_iter+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? lock_is_held_type+0x90/0x100
? srso_alias_return_thunk+0x5/0xfbef5
? __might_resched+0x278/0x360
? __pfx___might_resched+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
__skb_datagram_iter+0x2c2/0x460
? __pfx_simple_copy_to_iter+0x10/0x10
skb_copy_datagram_iter+0x6c/0x110
tcp_recvmsg_locked+0x9be/0xf40
? __pfx_tcp_recvmsg_locked+0x10/0x10
? mark_held_locks+0x5d/0x90
? srso_alias_return_thunk+0x5/0xfbef5
tcp_recvmsg+0xe2/0x310
? __pfx_tcp_recvmsg+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? lock_acquire+0x14a/0x3a0
? srso_alias_return_thunk+0x5/0xfbef5
inet_recvmsg+0xd0/0x370
? __pfx_inet_recvmsg+0x10/0x10
? __pfx_lock_release+0x10/0x10
? do_raw_spin_trylock+0xd1/0x120
sock_recvmsg+0x10d/0x150
cifs_readv_from_socket+0x25a/0x490 [cifs]
? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs]
? srso_alias_return_thunk+0x5/0xfbef5
cifs_read_from_socket+0xb5/0x100 [cifs]
? __pfx_cifs_read_from_socket+0x10/0x10 [cifs]
? __pfx_lock_release+0x10/0x10
? do_raw_spin_trylock+0xd1/0x120
? _raw_spin_unlock+0x23/0x40
? srso_alias_return_thunk+0x5/0xfbef5
? __smb2_find_mid+0x126/0x230 [cifs]
cifs_demultiplex_thread+0xd39/0x1270 [cifs]
? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
? __pfx_lock_release+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? mark_held_locks+0x1a/0x90
? lockdep_hardirqs_on_prepare+0x136/0x210
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __kthread_parkme+0xce/0xf0
? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
kthread+0x18d/0x1d0
? kthread+0xdb/0x1d0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>

Fixes: 8ce79ec359ad ("cifs: update multiplex loop to handle compounded responses")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix OOB in smb2_query_reparse_point()

Validate @ioctl_rsp->OutputOffset and @ioctl_rsp->OutputCount so that
their sum does not wrap to a number that is smaller than @reparse_buf
and we end up with a wild pointer as follows:

BUG: unable to handle page fault for address: ffff88809c5cd45f
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 4a01067 P4D 4a01067 PUD 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 2 PID: 1260 Comm: mount.cifs Not tainted 6.7.0-rc4 #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:smb2_query_reparse_point+0x3e0/0x4c0 [cifs]
Code: ff ff e8 f3 51 fe ff 41 89 c6 58 5a 45 85 f6 0f 85 14 fe ff ff
49 8b 57 48 8b 42 60 44 8b 42 64 42 8d 0c 00 49 39 4f 50 72 40 <8b>
04 02 48 8b 9d f0 fe ff ff 49 8b 57 50 89 03 48 8b 9d e8 fe ff
RSP: 0018:ffffc90000347a90 EFLAGS: 00010212
RAX: 000000008000001f RBX: ffff88800ae11000 RCX: 00000000000000ec
RDX: ffff88801c5cd440 RSI: 0000000000000000 RDI: ffffffff82004aa4
RBP: ffffc90000347bb0 R08: 00000000800000cd R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000024 R12: ffff8880114d4100
R13: ffff8880114d4198 R14: 0000000000000000 R15: ffff8880114d4000
FS: 00007f02c07babc0(0000) GS:ffff88806ba00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88809c5cd45f CR3: 0000000011750000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x181/0x480
? search_module_extables+0x19/0x60
? srso_alias_return_thunk+0x5/0xfbef5
? exc_page_fault+0x1b6/0x1c0
? asm_exc_page_fault+0x26/0x30
? _raw_spin_unlock_irqrestore+0x44/0x60
? smb2_query_reparse_point+0x3e0/0x4c0 [cifs]
cifs_get_fattr+0x16e/0xa50 [cifs]
? srso_alias_return_thunk+0x5/0xfbef5
? lock_acquire+0xbf/0x2b0
cifs_root_iget+0x163/0x5f0 [cifs]
cifs_smb3_do_mount+0x5bd/0x780 [cifs]
smb3_get_tree+0xd9/0x290 [cifs]
vfs_get_tree+0x2c/0x100
? capable+0x37/0x70
path_mount+0x2d7/0xb80
? srso_alias_return_thunk+0x5/0xfbef5
? _raw_spin_unlock_irqrestore+0x44/0x60
__x64_sys_mount+0x11a/0x150
do_syscall_64+0x47/0xf0
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f02c08d5b1e

Fixes: 2e4564b31b64 ("smb3: add support for stat of WSL reparse points for special file types")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix OOB in receive_encrypted_standard()

Fix potential OOB in receive_encrypted_standard() if server returned a
large shdr->NextCommand that would end up writing off the end of
@next_buffer.

Fixes: b24df3e30cbf ("cifs: update receive_encrypted_standard to handle compounded responses")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix potential NULL deref in parse_dfs_referrals()

If server returned no data for FSCTL_DFS_GET_REFERRALS, @dfs_rsp will
remain NULL and then parse_dfs_referrals() will dereference it.

Fix this by returning -EIO when no output data is returned.

Besides, we can't fix it in SMB2_ioctl() as some FSCTLs are allowed to
return no data as per MS-SMB2 2.2.32.

Fixes: 9d49640a21bf ("CIFS: implement get_dfs_refer for SMB2+")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: Fix FALLOC_FL_INSERT_RANGE by setting i_size after EOF moved

Fix the cifs filesystem implementations of FALLOC_FL_INSERT_RANGE, in
smb3_insert_range(), to set i_size after extending the file on the server
and before we do the copy to open the gap (as we don't clean up the EOF
marker if the copy fails).

Fixes: 7fe6fe95b936 ("cifs: add FALLOC_FL_INSERT_RANGE support")
Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: Fix FALLOC_FL_ZERO_RANGE by setting i_size if EOF moved

Fix the cifs filesystem implementations of FALLOC_FL_ZERO_RANGE, in
smb3_zero_range(), to set i_size after extending the file on the server.

Fixes: 72c419d9b073 ("cifs: fix smb3_zero_range so it can expand the file-size when required")
Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: introduce cifs_sfu_make_node()

Remove duplicate code and add new helper for creating special files in
SFU (Services for UNIX) format that can be shared by SMB1+ code.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: set correct file type from NFS reparse points

Handle all file types in NFS reparse points as specified in MS-FSCC
2.1.2.6 Network File System (NFS) Reparse Data Buffer.

The client is now able to set all file types based on the parsed NFS
reparse point, which used to support only symlinks. This works for
SMB1+.

Before patch:

$ mount.cifs //srv/share /mnt -o ...
$ ls -l /mnt
ls: cannot access 'block': Operation not supported
ls: cannot access 'char': Operation not supported
ls: cannot access 'fifo': Operation not supported
ls: cannot access 'sock': Operation not supported
total 1
l????????? ? ? ? ? ? block
l????????? ? ? ? ? ? char
-rwxr-xr-x 1 root root 5 Nov 18 23:22 f0
l????????? ? ? ? ? ? fifo
l--------- 1 root root 0 Nov 18 23:23 link -> f0
l????????? ? ? ? ? ? sock

After patch:

$ mount.cifs //srv/share /mnt -o ...
$ ls -l /mnt
total 1
brwxr-xr-x 1 root root 123, 123 Nov 18 00:34 block
crwxr-xr-x 1 root root 1234, 1234 Nov 18 00:33 char
-rwxr-xr-x 1 root root 5 Nov 18 23:22 f0
prwxr-xr-x 1 root root 0 Nov 18 23:23 fifo
lrwxr-xr-x 1 root root 0 Nov 18 23:23 link -> f0
srwxr-xr-x 1 root root 0 Nov 19 2023 sock

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: introduce ->parse_reparse_point()

Parse reparse point into cifs_open_info_data structure and feed it
through cifs_open_info_to_fattr().

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: implement ->query_reparse_point() for SMB1

Reparse points are not limited to symlinks, so implement
->query_reparse_point() in order to handle different file types.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: account for primary channel in the interface list

The refcounting of server interfaces should account
for the primary channel too. Although this is not
strictly necessary, doing so will account for the primary
channel in DebugData.

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb3: fix creating FIFOs when mounting with "sfu" mount option

Fixes some xfstests including generic/564 and generic/157

The "sfu" mount option can be useful for creating special files (character
and block devices in particular) but could not create FIFOs. It did
recognize existing empty files with the "system" attribute flag as FIFOs
but this is too general, so to support creating FIFOs more safely use a new
tag (but the same length as those for char and block devices ie "IntxLNK"
and "IntxBLK") "LnxFIFO" to indicate that the file should be treated as a
FIFO (when mounted with the "sfu"). For some additional context note that
"sfu" followed the way that "Services for Unix" on Windows handled these
special files (at least for character and block devices and symlinks),
which is different than newer Windows which can handle special files
as reparse points (which isn't an option to many servers).

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

client: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-66-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

smb3: correct places where ENOTSUPP is used instead of preferred EOPNOTSUPP

checkpatch flagged a few places with:
WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP
Also fixed minor typo

Signed-off-by: Steve French <stfrench@microsoft.com>

smb3: add trace point for queryfs (statfs)

In debugging a recent performance problem with statfs, it would have
been helpful to be able to trace the smb3 query fs info request
more narrowly. Add a trace point "smb3_qfs_done"

Which displays:

stat-68950 [008] ..... 1472.360598: smb3_qfs_done: xid=14 sid=0xaa9765e4 tid=0x95a76f54 unc_name=\\localhost\test rc=0

Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

SMB3: rename macro CIFS_SERVER_IS_CHAN to avoid confusion

Since older dialects such as CIFS do not support multichannel
the macro CIFS_SERVER_IS_CHAN can be confusing (it requires SMB 3
or later) so shorten its name to "SERVER_IS_CHAN"

Suggested-by: Tom Talpey <tom@talpey.com>
Acked-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

[SMB3] send channel sequence number in SMB3 requests after reconnects

The ChannelSequence field in the SMB3 header is supposed to be
increased after reconnect to allow the server to distinguish
requests from before and after the reconnect. We had always
been setting it to zero. There are cases where incrementing
ChannelSequence on requests after network reconnects can reduce
the chance of data corruptions.

See MS-SMB2 3.2.4.1 and 3.2.7.1

Signed-off-by: Steve French <stfrench@microsoft.com>
Cc: stable@vger.kernel.org # 5.16+

smb: client: reduce stack usage in smb2_query_reparse_point()

Clang warns about exceeded stack frame size

fs/smb/client/smb2ops.c:2973:12: warning: stack frame size (1336)
exceeds limit (1024) in 'smb2_query_reparse_point'
[-Wframe-larger-than]

Fix this by allocating a structure that will hold most of the large
variables.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: reduce stack usage in smb2_query_info_compound()

Clang warns about exceeded stack frame size

fs/smb/client/smb2ops.c:2521:1: warning: stack frame size (1336)
exceeds limit (1024) in 'smb2_query_info_compound'
[-Wframe-larger-than]

Fix this by allocating a structure that will hold most of the large
variables.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: reduce stack usage in smb2_set_ea()

Clang warns about exceeded stack frame size

fs/smb/client/smb2ops.c:1080:1: warning: stack frame size (1432)
exceeds limit (1024) in 'smb2_set_ea' [-Wframe-larger-than]

Fix this by allocating a structure that will hold most of the large
variables.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: query reparse points in older dialects

Enable the client to query reparse points in SMB2+.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: do not query reparse points twice on symlinks

Save a roundtrip by getting the reparse point tag and buffer at once
in ->query_reparse_point() and then pass the buffer down to
->query_symlink().

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Acked-by: Tom Talpey <tom@talpey.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Steve French <stfrench@microsoft.com>
Message-Id: <20230705190309.579783-72-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

cifs: is_network_name_deleted should return a bool

Currently, is_network_name_deleted and it's implementations
do not return anything if the network name did get deleted.
So the function doesn't fully achieve what it advertizes.

Changed the function to return a bool instead. It will now
return true if the error returned is STATUS_NETWORK_NAME_DELETED
and the share (tree id) was found to be connected. It returns
false otherwise.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: new dynamic tracepoint to track ses not found errors

It is perfectly valid to not find session not found errors
when a reconnect of a session happens when requests for the
same session are happening in parallel.

We had these log messages as VFS logs. My last change dumped
these logs as FYI logs.

This change just creates a new dynamic tracepoint to capture
events of this type, just in case it is useful while
debugging issues in the future.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: log session id when a matching ses is not found

We do not log the session id in crypt_setup when a matching
session is not found. Printing the session id helps debugging
here. This change does just that.

This change also changes this log to FYI, since it is normal to
see then during a reconnect. Doing the same for a similar log
in case of signed connections.

The plan is to have a tracepoint for this event, so that we will
be able to see this event if need be. That will be done as
another change.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: do all necessary checks for credits within or before locking

All the server credits and in-flight info is protected by req_lock.
Once the req_lock is held, and we've determined that we have enough
credits to continue, this lock cannot be dropped till we've made the
changes to credits and in-flight count.

However, we used to drop the lock in order to avoid deadlock with
the recent srv_lock. This could cause the checks already made to be
invalidated.

Fixed it by moving the server status check to before locking req_lock.

Fixes: d7d7a66aacd6 ("cifs: avoid use of global locks for high contention data")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb3: do not reserve too many oplock credits

There were cases reported where servers will sometimes return more
credits than requested on oplock break responses, which can lead to
most of the credits being allocated for oplock breaks (instead of
for normal operations like read and write) if number of SMB3 requests
in flight always stays above 0 (the oplock and echo credits are
rebalanced when in flight requests goes down to zero).

If oplock credits gets unexpectedly large (e.g. three is more than it
would ever be expected to be) and in flight requests are greater than
zero, then rebalance the oplock credits and regular credits (go
back to reserving just one oplock credit).

Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: add a warning when the in-flight count goes negative

We've seen the in-flight count go into negative with some
internal stress testing in Microsoft.

Adding a WARN when this happens, in hope of understanding
why this happens when it happens.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: fix max_credits implementation

The current implementation of max_credits on the client does
not work because the CreditRequest logic for several commands
does not take max_credits into account.

Still, we can end up asking the server for more credits, depending
on the number of credits in flight. For this, we need to
limit the credits while parsing the responses too.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: fix sockaddr comparison in iface_cmp

iface_cmp used to simply do a memcmp of the two
provided struct sockaddrs. The comparison needs to do more
based on the address family. Similar logic was already
present in cifs_match_ipaddr. Doing something similar now.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Drop the netfs_ prefix from netfs_extract_iter_to_sg()

Rename netfs_extract_iter_to_sg() and its auxiliary functions to drop the
netfs_ prefix.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-crypto@vger.kernel.org
cc: linux-cachefs@redhat.com
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: netdev@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

smb: delete an unnecessary statement

We don't need to set the list iterators to NULL before a
list_for_each_entry() loop because they are assigned inside the
macro.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: move client and server files to common directory fs/smb

Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko
and helper modules) to new fs/smb subdirectory:

fs/cifs --> fs/smb/client
fs/ksmbd --> fs/smb/server
fs/smbfs_common --> fs/smb/common

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>