Commit Graph

930 Commits

Author SHA1 Message Date
Al Viro de4eda9de2 use less confusing names for iov_iter direction initializers
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-25 13:01:55 -05:00
Zhang Xiaoxu 1dcdf5f5b2 cifs: Fix connections leak when tlink setup failed
If the tlink setup failed, lost to put the connections, then
the module refcnt leak since the cifsd kthread not exit.

Also leak the fscache info, and for next mount with fsc, it will
print the follow errors:
  CIFS: Cache volume key already in use (cifs,127.0.0.1:445,TEST)

Let's check the result of tlink setup, and do some cleanup.

Fixes: 56c762eb9b ("cifs: Refactor out cifs_mount()")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-11-11 11:59:30 -06:00
Zeng Heng 153695d36e cifs: fix use-after-free caused by invalid pointer `hostname`
`hostname` needs to be set as null-pointer after free in
`cifs_put_tcp_session` function, or when `cifsd` thread attempts
to resolve hostname and reconnect the host, the thread would deref
the invalid pointer.

Here is one of practical backtrace examples as reference:

Task 477
---------------------------
 do_mount
  path_mount
   do_new_mount
    vfs_get_tree
     smb3_get_tree
      smb3_get_tree_common
       cifs_smb3_do_mount
        cifs_mount
         mount_put_conns
          cifs_put_tcp_session
          --> kfree(server->hostname)

cifsd
---------------------------
 kthread
  cifs_demultiplex_thread
   cifs_reconnect
    reconn_set_ipaddr_from_hostname
    --> if (!server->hostname)
    --> if (server->hostname[0] == '\0')  // !! UAF fault here

CIFS: VFS: cifs_mount failed w/return code = -112
mount error(112): Host is down
BUG: KASAN: use-after-free in reconn_set_ipaddr_from_hostname+0x2ba/0x310
Read of size 1 at addr ffff888108f35380 by task cifsd/480
CPU: 2 PID: 480 Comm: cifsd Not tainted 6.1.0-rc2-00106-gf705792f89dd-dirty #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0x85
 print_report+0x16c/0x4a3
 kasan_report+0x95/0x190
 reconn_set_ipaddr_from_hostname+0x2ba/0x310
 __cifs_reconnect.part.0+0x241/0x800
 cifs_reconnect+0x65f/0xb60
 cifs_demultiplex_thread+0x1570/0x2570
 kthread+0x2c5/0x380
 ret_from_fork+0x22/0x30
 </TASK>
Allocated by task 477:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 __kasan_kmalloc+0x7e/0x90
 __kmalloc_node_track_caller+0x52/0x1b0
 kstrdup+0x3b/0x70
 cifs_get_tcp_session+0xbc/0x19b0
 mount_get_conns+0xa9/0x10c0
 cifs_mount+0xdf/0x1970
 cifs_smb3_do_mount+0x295/0x1660
 smb3_get_tree+0x352/0x5e0
 vfs_get_tree+0x8e/0x2e0
 path_mount+0xf8c/0x1990
 do_mount+0xee/0x110
 __x64_sys_mount+0x14b/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 477:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x2a/0x50
 __kasan_slab_free+0x10a/0x190
 __kmem_cache_free+0xca/0x3f0
 cifs_put_tcp_session+0x30c/0x450
 cifs_mount+0xf95/0x1970
 cifs_smb3_do_mount+0x295/0x1660
 smb3_get_tree+0x352/0x5e0
 vfs_get_tree+0x8e/0x2e0
 path_mount+0xf8c/0x1990
 do_mount+0xee/0x110
 __x64_sys_mount+0x14b/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888108f35380
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 0 bytes inside of
 16-byte region [ffff888108f35380, ffff888108f35390)
The buggy address belongs to the physical page:
page:00000000333f8e58 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888108f350e0 pfn:0x108f35
flags: 0x200000000000200(slab|node=0|zone=2)
raw: 0200000000000200 0000000000000000 dead000000000122 ffff8881000423c0
raw: ffff888108f350e0 000000008080007a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff888108f35280: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
 ffff888108f35300: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
>ffff888108f35380: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
                   ^
 ffff888108f35400: fa fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888108f35480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 7be3248f31 ("cifs: To match file servers, make sure the server hostname matches")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-27 23:59:13 -05:00
Enzo Matsumiya d7173623bf cifs: use ALIGN() and round_up() macros
Improve code readability by using existing macros:

Replace hardcoded alignment computations (e.g. (len + 7) & ~0x7) by
ALIGN()/IS_ALIGNED() macros.

Also replace (DIV_ROUND_UP(len, 8) * 8) with ALIGN(len, 8), which, if
not optimized by the compiler, has the overhead of a multiplication
and a division. Do the same for roundup() by replacing it by round_up()
(division-less version, but requires the multiple to be a power of 2,
which is always the case for us).

And remove some unnecessary checks where !IS_ALIGNED() would fit, but
calling round_up() directly is fine as it's a no-op if the value is
already aligned.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-13 09:36:39 -05:00
Ronnie Sahlberg 2f6f19c7aa cifs: fix regression in very old smb1 mounts
BZ: 215375

Fixes: 76a3c92ec9 ("cifs: remove support for NTLM and weaker authentication algorithms")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-13 09:35:07 -05:00
Enzo Matsumiya a4e430c8c8 cifs: replace kfree() with kfree_sensitive() for sensitive data
Replace kfree with kfree_sensitive, or prepend memzero_explicit() in
other cases, when freeing sensitive material that could still be left
in memory.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/r/202209201529.ec633796-oliver.sang@intel.com
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-07 23:06:48 -05:00
Steve French 4659f01e3c smb3: do not log confusing message when server returns no network interfaces
Some servers can return an empty network interface list so, unless
multichannel is requested, no need to log an error for this, and
when multichannel is requested on mount but no interfaces, log
something less confusing.  For this case change
   parse_server_interfaces: malformed interface info
to
   empty network interface list returned by server localhost

Also do not relog this error every ten minutes (only log on mount, once)

Cc: <stable@vger.kernel.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05 17:40:41 -05:00
Steve French 68e14569d7 smb3: add dynamic trace points for tree disconnect
Needed this for debugging a failing xfstest.
Also change camel case for "treeName" to "tree_name" in tcon struct.

Example trace output (from "trace-cmd record -e smb3_tdis*"):
          umount-9718    [006] .....  5909.780244: smb3_tdis_enter: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 path=\\localhost\test
          umount-9718    [007] .....  5909.780878: smb3_tdis_done: xid=206 sid=0xcf38894e tid=0x3d0b8cf8

Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05 01:31:18 -05:00
Paulo Alcantara 621a41ae08 cifs: add missing spinlock around tcon refcount
Add missing spinlock to protect updates on tcon refcount in
cifs_put_tcon().

Fixes: d7d7a66aac ("cifs: avoid use of global locks for high contention data")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-09-14 03:59:51 -05:00
Stefan Metzmacher bedc8f76b3 cifs: always initialize struct msghdr smb_msg completely
So far we were just lucky because the uninitialized members
of struct msghdr are not used by default on a SOCK_STREAM tcp
socket.

But as new things like msg_ubuf and sg_from_iter where added
recently, we should play on the safe side and avoid potention
problems in future.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-09-13 22:55:45 -05:00
Zhang Xiaoxu d291e703f4 cifs: Add helper function to check smb1+ server
SMB1 server's header_preamble_size is not 0, add use is_smb1 function
to simplify the code, no actual functional changes.

Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 22:30:09 -05:00
Zhang Xiaoxu b6b3624d01 cifs: Use help macro to get the mid header size
It's better to use MID_HEADER_SIZE because the unfolded expression
too long. No actual functional changes, minor readability improvement.

Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 22:30:04 -05:00
Zhang Xiaoxu 9789de8bdc cifs: Use help macro to get the header preamble size
It's better to use HEADER_PREAMBLE_SIZE because the unfolded expression
too long. No actual functional changes, minor readability improvement.

Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 22:29:59 -05:00
Wolfram Sang 13609a8b3a cifs: move from strlcpy with unused retval to strscpy
Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-19 11:02:26 -05:00
Steve French 5efdd9122e smb3: allow deferred close timeout to be configurable
Deferred close can be a very useful feature for allowing
caching data for read, and for minimizing the number of
reopens needed for a file that is repeatedly opened and
close but there are workloads where its default (1 second,
similar to actimeo/acregmax) is much too small.

Allow the user to configure the amount of time we can
defer sending the final smb3 close when we have a
handle lease on the file (rather than forcing it to depend
on value of actimeo which is often unrelated, and less safe).

Adds new mount parameter "closetimeo=" which is the maximum
number of seconds we can wait before sending an SMB3
close when we have a handle lease for it.  Default value
also is set to slightly larger at 5 seconds (although some
other clients use larger default this should still help).

Suggested-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-11 20:03:04 -05:00
Enzo Matsumiya 70f08f914a cifs: remove useless DeleteMidQEntry()
DeleteMidQEntry() was just a proxy for cifs_mid_q_entry_release().

- remove DeleteMidQEntry()
- rename cifs_mid_q_entry_release() to release_mid()
- rename kref_put() callback _cifs_mid_q_entry_release to __release_mid
- rename AllocMidQEntry() to alloc_mid()
- rename cifs_delete_mid() to delete_mid()

Update callers to use new names.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-05 11:24:06 -05:00
Steve French fb157ed226 cifs: when insecure legacy is disabled shrink amount of SMB1 code
Currently much of the smb1 code is built even when
CONFIG_CIFS_ALLOW_INSECURE_LEGACY is disabled.

Move cifssmb.c to only be compiled when insecure legacy is disabled,
and move various SMB1/CIFS helper functions to that ifdef.  Some
functions that were not SMB1/CIFS specific needed to be moved out of
cifssmb.c

This shrinks cifs.ko by more than 10% which is good - but also will
help with the eventual movement of the legacy code to a distinct
module.  Follow on patches can shrink the number of ifdefs by
code restructuring where smb1 code is wedged in functions that
should be calling dialect specific helper functions instead,
and also by moving some functions from file.c/dir.c/inode.c into
smb1 specific c files.

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-05 11:24:03 -05:00
Yang Yingliang aea02fc40a cifs: fix wrong unlock before return from cifs_tree_connect()
It should unlock 'tcon->tc_lock' before return from cifs_tree_connect().

Fixes: fe67bd563ec2 ("cifs: avoid use of global locks for high contention data")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:45 -05:00
Shyam Prasad N d7d7a66aac cifs: avoid use of global locks for high contention data
During analysis of multichannel perf, it was seen that
the global locks cifs_tcp_ses_lock and GlobalMid_Lock, which
were shared between various data structures were causing a
lot of contention points.

With this change, we're breaking down the use of these locks
by introducing new locks at more granular levels. i.e.
server->srv_lock, ses->ses_lock and tcon->tc_lock to protect
the unprotected fields of server, session and tcon structs;
and server->mid_lock to protect mid related lists and entries
at server level.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:45 -05:00
Enzo Matsumiya 9543c8ab30 cifs: list_for_each() -> list_for_each_entry()
Replace list_for_each() by list_for_each_entr() where appropriate.
Remove no longer used list_head stack variables.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:44 -05:00
Enzo Matsumiya da3847894f smb2: small refactor in smb2_check_message()
If the command is SMB2_IOCTL, OutputLength and OutputContext are
optional and can be zero, so return early and skip calculated length
check.

Move the mismatched length message to the end of the check, to avoid
unnecessary logs when the check was not a real miscalculation.

Also change the pr_warn_once() to a pr_warn() so we're sure to get a
log for the real mismatches.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:44 -05:00
Steve French c2c17ddbf3 cifs: remove some camelCase and also some static build warnings
Remove warnings for five global variables. For example:
  fs/cifs/cifsglob.h:1984:24: warning: symbol 'midCount' was not declared. Should it be static?

Also change them from camelCase (e.g. "midCount" to "mid_count")

Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:44 -05:00
Yu Zhe 0f46608ae7 cifs: remove unnecessary type castings
remove unnecessary void* type castings.

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:44 -05:00
Shyam Prasad N 2883f4b5a0 cifs: remove unnecessary locking of chan_lock while freeing session
In cifs_put_smb_ses, when we're freeing the last ref count to
the session, we need to free up each channel. At this point,
it is unnecessary to take chan_lock, since we have the last
reference to the ses.

Picking up this lock also introduced a deadlock because it calls
cifs_put_tcp_ses, which locks cifs_tcp_ses_lock.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-07-12 10:35:48 -05:00
Paulo Alcantara af3a6d1018 cifs: update cifs_ses::ip_addr after failover
cifs_ses::ip_addr wasn't being updated in cifs_session_setup() when
reconnecting SMB sessions thus returning wrong value in
/proc/fs/cifs/DebugData.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-24 13:34:28 -05:00
Shyam Prasad N 8da33fd11c cifs: avoid deadlocks while updating iface
We use cifs_tcp_ses_lock to protect a lot of things.
Not only does it protect the lists of connections, sessions,
tree connects, open file lists, etc., we also use it to
protect some fields in each of it's entries.

In this case, cifs_mark_ses_for_reconnect takes the
cifs_tcp_ses_lock to traverse the lists, and then calls
cifs_update_iface. However, that can end up calling
cifs_put_tcp_session, which picks up the same lock again.

Avoid this by taking a ref for the session, drop the lock,
and then call update iface.

Also, in cifs_update_iface, avoid nested locking of iface_lock
and chan_lock, as much as possible. When unavoidable, we need
to pick iface_lock first.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-24 09:17:56 -05:00
Shyam Prasad N 6e1c1c08cd cifs: periodically query network interfaces from server
Currently, we only query the server for network interfaces
information at the time of mount, and never afterwards.
This can be a problem, especially for services like Azure,
where the IP address of the channel endpoints can change
over time.

With this change, we schedule a 600s polling of this info
from the server for each tree connect.

An alternative for periodic polling was to do this only at
the time of reconnect. But this could delay the reconnect
time slightly. Also, there are some challenges w.r.t how
we have cifs_reconnect implemented today.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-22 19:51:43 -05:00
Shyam Prasad N b54034a73b cifs: during reconnect, update interface if necessary
Going forward, the plan is to periodically query the server
for it's interfaces (when multichannel is enabled).

This change allows checking for inactive interfaces during
reconnect, and reconnect to a new interface if necessary.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-22 19:51:43 -05:00
Shyam Prasad N aa45dadd34 cifs: change iface_list from array to sorted linked list
A server's published interface list can change over time, and needs
to be updated. We've storing iface_list as a simple array, which
makes it difficult to manipulate an existing list.

With this change, iface_list is modified into a linked list of
interfaces, which is kept sorted by speed.

Also added a reference counter for an iface entry, so that each
channel can maintain a backpointer to the iface and drop it
easily when needed.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-22 19:51:43 -05:00
Shyam Prasad N 4c14d7043f cifs: populate empty hostnames for extra channels
Currently, the secondary channels of a multichannel session
also get hostname populated based on the info in primary channel.
However, this will end up with a wrong resolution of hostname to
IP address during reconnect.

This change fixes this by not populating hostname info for all
secondary channels.

Fixes: 5112d80c16 ("cifs: populate server_hostname for extra channels")
Cc: stable@vger.kernel.org
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-10 18:55:02 -05:00
Vincent Whitchurch cc391b694f cifs: fix potential deadlock in direct reclaim
The srv_mutex is used during writeback so cifs should ensure that
allocations done when that mutex is held are done with GFP_NOFS, to
avoid having direct reclaim ending up waiting for the same mutex and
causing a deadlock.  This is detected by lockdep with the splat below:

 ======================================================
 WARNING: possible circular locking dependency detected
 5.18.0 #70 Not tainted
 ------------------------------------------------------
 kswapd0/49 is trying to acquire lock:
 ffff8880195782e0 (&tcp_ses->srv_mutex){+.+.}-{3:3}, at: compound_send_recv

 but task is already holding lock:
 ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (fs_reclaim){+.+.}-{0:0}:
        fs_reclaim_acquire
        kmem_cache_alloc_trace
        __request_module
        crypto_alg_mod_lookup
        crypto_alloc_tfm_node
        crypto_alloc_shash
        cifs_alloc_hash
        smb311_crypto_shash_allocate
        smb311_update_preauth_hash
        compound_send_recv
        cifs_send_recv
        SMB2_negotiate
        smb2_negotiate
        cifs_negotiate_protocol
        cifs_get_smb_ses
        cifs_mount
        cifs_smb3_do_mount
        smb3_get_tree
        vfs_get_tree
        path_mount
        __x64_sys_mount
        do_syscall_64
        entry_SYSCALL_64_after_hwframe

 -> #0 (&tcp_ses->srv_mutex){+.+.}-{3:3}:
        __lock_acquire
        lock_acquire
        __mutex_lock
        mutex_lock_nested
        compound_send_recv
        cifs_send_recv
        SMB2_write
        smb2_sync_write
        cifs_write
        cifs_writepage_locked
        cifs_writepage
        shrink_page_list
        shrink_lruvec
        shrink_node
        balance_pgdat
        kswapd
        kthread
        ret_from_fork

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(fs_reclaim);
                                lock(&tcp_ses->srv_mutex);
                                lock(fs_reclaim);
   lock(&tcp_ses->srv_mutex);

  *** DEADLOCK ***

 1 lock held by kswapd0/49:
  #0: ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat

 stack backtrace:
 CPU: 2 PID: 49 Comm: kswapd0 Not tainted 5.18.0 #70
 Call Trace:
  <TASK>
  dump_stack_lvl
  dump_stack
  print_circular_bug.cold
  check_noncircular
  __lock_acquire
  lock_acquire
  __mutex_lock
  mutex_lock_nested
  compound_send_recv
  cifs_send_recv
  SMB2_write
  smb2_sync_write
  cifs_write
  cifs_writepage_locked
  cifs_writepage
  shrink_page_list
  shrink_lruvec
  shrink_node
  balance_pgdat
  kswapd
  kthread
  ret_from_fork
  </TASK>

Fix this by using the memalloc_nofs_save/restore APIs around the places
where the srv_mutex is held.  Do this in a wrapper function for the
lock/unlock of the srv_mutex, and rename the srv_mutex to avoid missing
call sites in the conversion.

Note that there is another lockdep warning involving internal crypto
locks, which was masked by this problem and is visible after this fix,
see the discussion in this thread:

 https://lore.kernel.org/all/20220523123755.GA13668@axis.com/

Link: https://lore.kernel.org/r/CANT5p=rqcYfYMVHirqvdnnca4Mo+JQSw5Qu12v=kPfpk5yhhmg@mail.gmail.com/
Reported-by: Shyam Prasad N <nspmangalore@gmail.com>
Suggested-by: Lars Persson <larper@axis.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-01 00:03:18 -05:00
Enzo Matsumiya 0d5106a80e cifs: remove repeated debug message on cifs_put_smb_ses()
Similar message is printed a few lines later in the same function

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-31 15:09:51 -05:00
Paulo Alcantara de3a9e943d cifs: fix ntlmssp on old servers
Some older servers seem to require the workstation name during ntlmssp
to be at most 15 chars (RFC1001 name length), so truncate it before
sending when using insecure dialects.

Link: https://lore.kernel.org/r/e6837098-15d9-acb6-7e34-1923cf8c6fe1@winds.org
Reported-by: Byron Stanoszek <gandalf@winds.org>
Tested-by: Byron Stanoszek <gandalf@winds.org>
Fixes: 49bd49f983 ("cifs: send workstation name during ntlmssp session setup")
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-25 07:41:22 -05:00
Shyam Prasad N 5752bf645f cifs: avoid parallel session setups on same channel
After allowing channels to reconnect in parallel, it now
becomes important to take care that multiple processes do not
call negotiate/session setup in parallel on the same channel.

This change avoids that by marking a channel as "in_reconnect".
During session setup if the channel in question has this flag
set, we return immediately.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-24 14:16:32 -05:00
Shyam Prasad N dd3cd8709e cifs: use new enum for ses_status
ses->status today shares statusEnum with server->tcpStatus.
This has been confusing, and tcon->status has deviated to use
a new enum. Follow suit and use new enum for ses_status as well.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-24 14:11:17 -05:00
Shyam Prasad N 1a6a41d4ce cifs: do not use tcpStatus after negotiate completes
Recent changes to multichannel to allow channel reconnects to
work in parallel and independent of each other did so by
making use of tcpStatus for the connection, and status for the
session. However, this did not take into account the multiuser
scenario, where same connection is used by multiple connections.

However, tcpStatus should be tracked only till the end of
negotiate exchange, and not used for session setup. This change
fixes this.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-24 14:08:25 -05:00
Steve French 52832252dd smb3: add mount parm nosparse
To reduce risk of applications breaking that mount to servers
with only partial sparse file support, add optional mount parm
"nosparse" which disables setting files sparse (and thus
will return EOPNOTSUPP on certain fallocate operations).

Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-23 23:32:54 -05:00
Steve French 93ed91c020 cifs: fix minor compile warning
Add ifdef around nodfs variable from patch:
  "cifs: don't call cifs_dfs_query_info_nonascii_quirk() if nodfs was set"
which is unused when CONFIG_DFS_UPCALL is not set.

Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-23 20:24:12 -05:00
Enzo Matsumiya 71081e7ac1 cifs: print TIDs as hex
Makes these debug messages easier to read

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-20 17:46:22 -05:00
Enzo Matsumiya 337b8b0e43 cifs: return ENOENT for DFS lookup_cache_entry()
EEXIST didn't make sense to use when dfs_cache_find() couldn't find a
cache entry nor retrieve a referral target.

It also doesn't make sense cifs_dfs_query_info_nonascii_quirk() to
emulate ENOENT anymore.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-20 17:44:34 -05:00
Enzo Matsumiya 421ef3d565 cifs: don't call cifs_dfs_query_info_nonascii_quirk() if nodfs was set
Also return EOPNOTSUPP if path is remote but nodfs was set.

Fixes: a2809d0e16 ("cifs: quirk for STATUS_OBJECT_NAME_INVALID returned for non-ASCII dfs refs")
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-20 17:38:11 -05:00
Paulo Alcantara cd70a3e898 cifs: use correct lock type in cifs_reconnect()
TCP_Server_Info::origin_fullpath and TCP_Server_Info::leaf_fullpath
are protected by refpath_lock mutex and not cifs_tcp_ses_lock
spinlock.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-20 22:54:39 -05:00
Paulo Alcantara 41f10081a9 cifs: fix NULL ptr dereference in refresh_mounts()
Either mount(2) or automount might not have server->origin_fullpath
set yet while refresh_cache_worker() is attempting to refresh DFS
referrals.  Add missing NULL check and locking around it.

This fixes bellow crash:

[ 1070.276835] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 1070.277676] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 1070.278219] CPU: 1 PID: 8506 Comm: kworker/u8:1 Not tainted 5.18.0-rc3 #10
[ 1070.278701] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[ 1070.279495] Workqueue: cifs-dfscache refresh_cache_worker [cifs]
[ 1070.280044] RIP: 0010:strcasecmp+0x34/0x150
[ 1070.280359] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44
[ 1070.281729] RSP: 0018:ffffc90008367958 EFLAGS: 00010246
[ 1070.282114] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
[ 1070.282691] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 1070.283273] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27
[ 1070.283857] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000
[ 1070.284436] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000
[ 1070.284990] FS:  0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000
[ 1070.285625] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1070.286100] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0
[ 1070.286683] Call Trace:
[ 1070.286890]  <TASK>
[ 1070.287070]  refresh_cache_worker+0x895/0xd20 [cifs]
[ 1070.287475]  ? __refresh_tcon.isra.0+0xfb0/0xfb0 [cifs]
[ 1070.287905]  ? __lock_acquire+0xcd1/0x6960
[ 1070.288247]  ? is_dynamic_key+0x1a0/0x1a0
[ 1070.288591]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[ 1070.289012]  ? lock_downgrade+0x6f0/0x6f0
[ 1070.289318]  process_one_work+0x7bd/0x12d0
[ 1070.289637]  ? worker_thread+0x160/0xec0
[ 1070.289970]  ? pwq_dec_nr_in_flight+0x230/0x230
[ 1070.290318]  ? _raw_spin_lock_irq+0x5e/0x90
[ 1070.290619]  worker_thread+0x5ac/0xec0
[ 1070.290891]  ? process_one_work+0x12d0/0x12d0
[ 1070.291199]  kthread+0x2a5/0x350
[ 1070.291430]  ? kthread_complete_and_exit+0x20/0x20
[ 1070.291770]  ret_from_fork+0x22/0x30
[ 1070.292050]  </TASK>
[ 1070.292223] Modules linked in: bpfilter cifs cifs_arc4 cifs_md4
[ 1070.292765] ---[ end trace 0000000000000000 ]---
[ 1070.293108] RIP: 0010:strcasecmp+0x34/0x150
[ 1070.293471] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44
[ 1070.297718] RSP: 0018:ffffc90008367958 EFLAGS: 00010246
[ 1070.298622] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
[ 1070.299428] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 1070.300296] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27
[ 1070.301204] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000
[ 1070.301932] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000
[ 1070.302645] FS:  0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000
[ 1070.303462] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1070.304131] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0
[ 1070.305004] Kernel panic - not syncing: Fatal exception
[ 1070.305711] Kernel Offset: disabled
[ 1070.305971] ---[ end Kernel panic - not syncing: Fatal exception ]---

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-20 22:54:17 -05:00
David Howells 1ddff77416 cifs: Split the smb3_add_credits tracepoint
Split the smb3_add_credits tracepoint to make it more obvious when looking
at the logs which line corresponds to what credit change.  Also add a
tracepoint for credit overflow when it's being added back.

Note that it might be better to add another field to the tracepoint for
the information rather than splitting it.  It would also be useful to store
the MID potentially, though that isn't available when the credits are first
obtained.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: linux-cifs@vger.kernel.org
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-08 21:25:38 -05:00
Paulo Alcantara fb39d30e22 cifs: force new session setup and tcon for dfs
Do not reuse existing sessions and tcons in DFS failover as it might
connect to different servers and shares.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-04 22:39:21 -05:00
Paulo Alcantara 687127c81a cifs: fix potential race with cifsd thread
To avoid racing with demultiplex thread while it is handling data on
socket, use cifs_signal_cifsd_for_reconnect() helper for marking
current server to reconnect and let the demultiplex thread handle the
rest.

Fixes: dca65818c8 ("cifs: use a different reconnect helper for non-cifsd threads")
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-04 12:01:22 -05:00
Steve French fdf59eb548 smb3: cleanup and clarify status of tree connections
Currently the way the tid (tree connection) status is tracked
is confusing.  The same enum is used for structs cifs_tcon
and cifs_ses and TCP_Server_info, but each of these three has
different states that they transition among.  The current
code also unnecessarily uses camelCase.

Convert from use of statusEnum to a new tid_status_enum for
tree connections.  The valid states for a tid are:

        TID_NEW = 0,
        TID_GOOD,
        TID_EXITING,
        TID_NEED_RECON,
        TID_NEED_TCON,
        TID_IN_TCON,
        TID_NEED_FILES_INVALIDATE, /* unused, considering removing in future */
        TID_IN_FILES_INVALIDATE

It also removes CifsNeedTcon, CifsInTcon, CifsNeedFilesInvalidate and
CifsInFilesInvalidate from the statusEnum used for session and
TCP_Server_Info since they are not relevant for those.

A follow on patch will fix the places where we use the
tcon->need_reconnect flag to be more consistent with the tid->status.

Also fixes a bug that was:
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-28 17:07:30 -05:00
Paulo Alcantara 5d7e282541 cifs: do not skip link targets when an I/O fails
When I/O fails in one of the currently connected DFS targets, retry it
from other targets as specified in MS-DFSC "3.1.5.2 I/O Operation to
+Target Fails with an Error Other Than STATUS_PATH_NOT_COVERED."

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-21 23:30:14 -05:00
Shyam Prasad N dca65818c8 cifs: use a different reconnect helper for non-cifsd threads
The cifs_demultiplexer_thread should only call cifs_reconnect.
If any other thread wants to trigger a reconnect, they can do
so by updating the server tcpStatus to CifsNeedReconnect.

The last patch attempted to use the same helper function for
both types of threads, but that causes other issues
with lock dependencies.

This patch creates a new helper for non-cifsd threads, that
will indicate to cifsd that the server needs reconnect.

Fixes: 2a05137a05 ("cifs: mark sessions for reconnection in helper function")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-18 23:12:03 -05:00
Steve French e3ee9fb226 smb3: fix incorrect session setup check for multiuser mounts
A recent change to how the SMB3 server (socket) and session status
is managed regressed multiuser mounts by changing the check
for whether session setup is needed to the socket (TCP_Server_info)
structure instead of the session struct (cifs_ses). Add additional
check in cifs_setup_sesion to fix this.

Fixes: 73f9bfbe3d ("cifs: maintain a state machine for tcp/smb/tcon sessions")
Reported-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-16 22:48:55 -05:00