Commit Graph

73 Commits

Author SHA1 Message Date
Shyam Prasad N 2f0e4f0342 cifs: check only tcon status on tcon related functions
We had a couple of checks for session in cifs_tree_connect
and cifs_mark_open_files_invalid, which were unnecessary.
And that was done with ses_lock. Changed that to tc_lock too.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-03-17 13:22:22 -05:00
Paulo Alcantara 396935de14 cifs: fix use-after-free bug in refresh_cache_worker()
The UAF bug occurred because we were putting DFS root sessions in
cifs_umount() while DFS cache refresher was being executed.

Make DFS root sessions have same lifetime as DFS tcons so we can avoid
the use-after-free bug is DFS cache refresher and other places that
require IPCs to get new DFS referrals on.  Also, get rid of mount
group handling in DFS cache as we no longer need it.

This fixes below use-after-free bug catched by KASAN

[ 379.946955] BUG: KASAN: use-after-free in __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.947642] Read of size 8 at addr ffff888018f57030 by task kworker/u4:3/56
[ 379.948096]
[ 379.948208] CPU: 0 PID: 56 Comm: kworker/u4:3 Not tainted 6.2.0-rc7-lku #23
[ 379.948661] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014
[ 379.949368] Workqueue: cifs-dfscache refresh_cache_worker [cifs]
[ 379.949942] Call Trace:
[ 379.950113] <TASK>
[ 379.950260] dump_stack_lvl+0x50/0x67
[ 379.950510] print_report+0x16a/0x48e
[ 379.950759] ? __virt_addr_valid+0xd8/0x160
[ 379.951040] ? __phys_addr+0x41/0x80
[ 379.951285] kasan_report+0xdb/0x110
[ 379.951533] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.952056] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.952585] __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.953096] ? __pfx___refresh_tcon.isra.0+0x10/0x10 [cifs]
[ 379.953637] ? __pfx___mutex_lock+0x10/0x10
[ 379.953915] ? lock_release+0xb6/0x720
[ 379.954167] ? __pfx_lock_acquire+0x10/0x10
[ 379.954443] ? refresh_cache_worker+0x34e/0x6d0 [cifs]
[ 379.954960] ? __pfx_wb_workfn+0x10/0x10
[ 379.955239] refresh_cache_worker+0x4ad/0x6d0 [cifs]
[ 379.955755] ? __pfx_refresh_cache_worker+0x10/0x10 [cifs]
[ 379.956323] ? __pfx_lock_acquired+0x10/0x10
[ 379.956615] ? read_word_at_a_time+0xe/0x20
[ 379.956898] ? lockdep_hardirqs_on_prepare+0x12/0x220
[ 379.957235] process_one_work+0x535/0x990
[ 379.957509] ? __pfx_process_one_work+0x10/0x10
[ 379.957812] ? lock_acquired+0xb7/0x5f0
[ 379.958069] ? __list_add_valid+0x37/0xd0
[ 379.958341] ? __list_add_valid+0x37/0xd0
[ 379.958611] worker_thread+0x8e/0x630
[ 379.958861] ? __pfx_worker_thread+0x10/0x10
[ 379.959148] kthread+0x17d/0x1b0
[ 379.959369] ? __pfx_kthread+0x10/0x10
[ 379.959630] ret_from_fork+0x2c/0x50
[ 379.959879] </TASK>

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-03-14 21:07:44 -05:00
Paulo Alcantara a1b7c8457e cifs: remove unused function
Remove dfs_cache_update_tgthint() as it is not used anywhere.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 14:49:51 -06:00
Paulo Alcantara d6a49e8c4c cifs: fix return of uninitialized rc in dfs_cache_update_tgthint()
Fix this by initializing rc to 0 as cache_refresh_path() would not set
it in case of success.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/all/202301190004.bEHvbKG6-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 11:24:20 -06:00
Paulo Alcantara 3deddb77fd cifs: handle cache lookup errors different than -ENOENT
lookup_cache_entry() might return an error different than -ENOENT
(e.g. from ->char2uni), so handle those as well in
cache_refresh_path().

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 10:45:58 -06:00
Paulo Alcantara 8064f711c6 cifs: remove duplicate code in __refresh_tcon()
The logic for creating or updating a cache entry in __refresh_tcon()
could be simply done with cache_refresh_path(), so use it instead.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 10:45:58 -06:00
Paulo Alcantara 11c8b3f849 cifs: don't take exclusive lock for updating target hints
Avoid contention while updating dfs target hints.  This should be
perfectly fine to update them under shared locks.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 10:45:58 -06:00
Paulo Alcantara 48d240bf00 cifs: avoid re-lookups in dfs_cache_find()
Simply downgrade the write lock on cache updates from
cache_refresh_path() and avoid unnecessary re-lookup in
dfs_cache_find().

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 10:45:58 -06:00
Paulo Alcantara 9fb0db4051 cifs: fix potential deadlock in cache_refresh_path()
Avoid getting DFS referral from an exclusive lock in
cache_refresh_path() because the tcon IPC used for getting the
referral could be disconnected and thus causing a deadlock as shown
below:

task A                       task B
======                       ======
cifs_demultiplex_thread()    dfs_cache_find()
 cifs_handle_standard()       cache_refresh_path()
  reconnect_dfs_server()       down_write()
   dfs_cache_noreq_find()       get_dfs_referral()
    down_read() <- deadlock      smb2_get_dfs_refer()
                                  SMB2_ioctl()
				   cifs_send_recv()
				    compound_send_recv()
				     wait_for_response()

where task A cannot wake up task B because it is blocked on
down_read() due to the exclusive lock held in cache_refresh_path() and
therefore not being able to make progress.

Fixes: c9f7110399 ("cifs: keep referral server sessions alive")
Reviewed-by: Aurélien Aptel <aurelien.aptel@gmail.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-18 10:45:40 -06:00
Colin Ian King 2f57e4464c cifs: remove redundant assignment to the variable match
The variable match is being assigned a value that is never read, it
is being re-assigned a new value later on. The assignment is redundant
and can be removed.

Cleans up clang scan-build warning:
fs/cifs/dfs_cache.c:1302:2: warning: Value stored to 'match' is never read

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-10 15:31:08 -06:00
Paulo Alcantara 1d04a6fe75 cifs: don't block in dfs_cache_noreq_update_tgthint()
Avoid blocking in dfs_cache_noreq_update_tgthint() while reconnecting
servers or tcons as the cache refresh worker or new mounts might
already be updating their targets.

Move some more dfs related code out of connect.c while at it.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara 8332858569 cifs: refresh root referrals
Also refresh cached root referrals so the other cached referrals may
have a better chance to have a working root server to issue the
referrals on.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara 6916881f44 cifs: fix refresh of cached referrals
We can't rely on cifs_tcon::ses to refresh cached referral as the
server target might not respond to referrals, e.g. share is not hosted
in a DFS root server.  Consider the following

  mount //dom/dfs/link -> /root1/dfs/link -> /fs0/share

where fs0 can't get a referral for "/root1/dfs/link".

To simplify and fix the access of dfs root sessions, store the dfs
root session pointer directly to new sessions so making it easier to
select the appropriate ipc connection and use it for failover or cache
refresh.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara cb3f6d8764 cifs: don't refresh cached referrals from unactive mounts
There is no point refreshing cached referrals from unactive mounts as
they will no longer be used and new mounts will either create or
refresh them anyway.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara a1c0d00572 cifs: share dfs connections and supers
When matching DFS superblocks we can't rely on either the server's
address or tcon's UNC name from mount(2) as the existing servers and
tcons might be connected to somewhere else.  Instead, check if
superblock is dfs, and if so, match its original source pathname with
the new mount's source pathname.

For DFS connections, instead of checking server's address, match its
referral path as it could be connected to different targets.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara 6d740164d8 cifs: set resolved ip in sockaddr
All callers from dns_resolve_server_name_to_ip() used to convert the
ip addr string back to sockaddr, so do that inside
dns_resolve_server_name_to_ip() and avoid duplicating code.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:11 -06:00
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
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
Steve French ee3c8019cc cifs: fix uninitialized pointer in error case in dfs_cache_get_tgt_share
Set default value of ppath to null.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-04 13:33:42 -05:00
Paulo Alcantara ef605e8682 cifs: skip trailing separators of prefix paths
During DFS failover, prefix paths may change, so make sure to not
leave trailing separators when parsing thew in
dfs_cache_get_tgt_share().  The separators of prefix paths are already
handled by build_path_from_dentry_optional_prefix().

Consider the following DFS link:

  //dom/dfs/link: [\srv1\share\dir1, \srv2\share\dir1]

Before commit:

  mount.cifs //dom/dfs/link
  tree connect to \\srv1\share; prefix_path=dir1
  disconnect srv1; failover to srv2
  tree connect to \\srv2\share; prefix_path=dir1\
  mv foo bar

  ...
  SMB2 430 Create Request File: dir1\\foo;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 582 Create Response File: dir1\\foo;GetInfo Response;Close Response
  SMB2 430 Create Request File: dir1\\bar;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 286 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;GetInfo Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;Close Response, Error: STATUS_OBJECT_NAME_NOT_FOUND
  SMB2 462 Create Request File: dir1\\foo;SetInfo Request FILE_INFO/SMB2_FILE_RENAME_INFO NewName:dir1\\bar;Close Request
  SMB2 478 Create Response File: dir1\\foo;SetInfo Response, Error: STATUS_OBJECT_NAME_INVALID;Close Response

After commit:

  mount.cifs //dom/dfs/link
  tree connect to \\srv1\share; prefix_path=dir1
  disconnect srv1; failover to srv2
  tree connect to \\srv2\share; prefix_path=dir1
  mv foo bar

  ...
  SMB2 430 Create Request File: dir1\foo;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 582 Create Response File: dir1\foo;GetInfo Response;Close Response
  SMB2 430 Create Request File: dir1\bar;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 286 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;GetInfo Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;Close Response, Error: STATUS_OBJECT_NAME_NOT_FOUND
  SMB2 462 Create Request File: dir1\foo;SetInfo Request FILE_INFO/SMB2_FILE_RENAME_INFO NewName:dir1\bar;Close Request
  SMB2 478 Create Response File: dir1\foo;SetInfo Response;Close Response

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-03 14:14:58 -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 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
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
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
Shyam Prasad N 52492ff5c5 cifs: call helper functions for marking channels for reconnect
cifs_mark_tcp_ses_conns_for_reconnect helper function is now
meant to be used by any of the threads to mark a channel
(or all the channels) for reconnect.

Replace all such manual changes to tcpStatus to use this
helper function, which takes care that the right channels,
smb sessions and tcons are marked for reconnect.

Also includes one line minor change
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-02-08 22:13:48 -06:00
Shyam Prasad N ba978e8325 cifs: cifs_ses_mark_for_reconnect should also update reconnect bits
Recent restructuring of cifs_reconnect introduced a helper func
named cifs_ses_mark_for_reconnect, which updates the state of tcp
session for all the channels of a session for reconnect.

However, this does not update the session state and chans_need_reconnect
bitmask. This change fixes that.

Also, cifs_mark_tcp_sess_for_reconnect should mark set the bitmask
for all channels when the whole session is marked for reconnect.
Fixed that here too.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-19 11:10:58 -06:00
Paulo Alcantara 8ae87bbeb5 cifs: introduce cifs_ses_mark_for_reconnect() helper
Use new cifs_ses_mark_for_reconnect() helper to mark all session
channels for reconnect instead of duplicating it in different places.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-16 10:57:08 -06:00
Paulo Alcantara c88f7dcd6d cifs: support nested dfs links over reconnect
Mounting a dfs link that has nested links was already supported at
mount(2), so make it work over reconnect as well.

Make the following case work:

* mount //root/dfs/link /mnt -o ...
  - final share: /server/share

* in server settings
  - change target folder of /root/dfs/link3 to /server/share2
  - change target folder of /root/dfs/link2 to /root/dfs/link3
  - change target folder of /root/dfs/link to /root/dfs/link2

* mount -o remount,... /mnt
 - refresh all dfs referrals
 - mark current connection for failover
 - cifs_reconnect() reconnects to root server
 - tree_connect()
   * checks that /root/dfs/link2 is a link, then chase it
   * checks that root/dfs/link3 is a link, then chase it
   * finally tree connect to /server/share2

If the mounted share is no longer accessible and a reconnect had been
triggered, the client will retry it from both last referral
path (/root/dfs/link3) and original referral path (/root/dfs/link).

Any new referral paths found while chasing dfs links over reconnect,
it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-10 16:30:13 -06:00
Paulo Alcantara efb21d7b0f cifs: fix print of hdr_flags in dfscache_proc_show()
Reorder the parameters in seq_printf() to correctly print header
flags.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-09 20:44:07 -06:00
Paulo Alcantara b62366181a cifs: support share failover when remounting
When remouting a DFS share, force a new DFS referral of the path and
if the currently cached targets do not match any of the new targets or
there was no cached targets, then mark it for reconnect.

For example:

    $ mount //dom/dfs/link /mnt -o username=foo,password=bar
    $ ls /mnt
    oldfile.txt

    change target share of 'link' in server settings

    $ mount /mnt -o remount,username=foo,password=bar
    $ ls /mnt
    newfile.txt

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-22 11:43:23 -05:00
Paulo Alcantara 889c2a7007 cifs: fix check of dfs interlinks
Interlink is a special type of DFS link that resolves to a different
DFS domain-based namespace.  To determine whether it is an interlink
or not, check if ReferralServers and StorageServers bits are set to 1
and 0 respectively in ReferralHeaderFlags, as specified in MS-DFSC
3.1.5.4.5 Determining Whether a Referral Response is an Interlink.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara 1023e90b73 cifs: avoid starvation when refreshing dfs cache
When refreshing the DFS cache, keep SMB2 IOCTL calls as much outside
critical sections as possible and avoid read/write starvation when
getting new DFS referrals by using broken or slow connections.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara c950fc7af9 cifs: set a minimum of 2 minutes for refreshing dfs cache
We don't want to refresh the dfs cache in very short intervals, so
setting a minimum interval of 2 minutes is OK.

If it needs to be refreshed immediately, one could have the cache
cleared with

	$ echo 0 > /proc/fs/cifs/dfscache

and then remounting the dfs share.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara 42caeba713 cifs: fix path comparison and hash calc
Fix cache lookup and hash calculations when handling paths with
different cases.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara c870a8e70e cifs: handle different charsets in dfs cache
Convert all dfs paths to dfs cache's local codepage (@cache_cp) and
avoid mixing them with different charsets.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Paulo Alcantara c9f7110399 cifs: keep referral server sessions alive
At every mount, keep all sessions alive that were used for chasing the
DFS referrals as long as the dfs mounts are active.

Use those sessions in DFS cache to refresh all active tcons as well as
cached entries.  They will be managed by a list of mount_group
structures that will be indexed by a randomly generated uuid at mount
time, so we can put all the sessions related to specific dfs mounts
and avoid leaking them.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Paulo Alcantara 2b133b7e21 cifs: get rid of @noreq param in __dfs_cache_find()
@noreq param isn't used anywhere, so just remove it.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
YueHaibing a23a71abca cifs: Remove unused inline function is_sysvol_or_netlogon()
is_sysvol_or_netlogon() is never used, so can remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Al Viro 9cfdb1c12b cifs: constify get_normalized_path() properly
As it is, it takes const char * and, in some cases, stores it in
caller's variable that is plain char *.  Fortunately, none of the
callers actually proceeded to modify the string via now-non-const
alias, but that's trouble waiting to happen.

It's easy to do properly, anyway...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-25 16:28:23 -05:00
Al Viro 8d76722355 cifs: don't cargo-cult strndup()
strndup(s, strlen(s)) is a highly unidiomatic way to spell strdup(s);
it's *NOT* safer in any way, since strlen() is just as sensitive to
NUL-termination as strdup() is.

strndup() is for situations when you need a copy of a known-sized
substring, not a magic security juju to drive the bad spirits away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-25 16:28:23 -05:00
Paulo Alcantara 5ff2836ed3 cifs: introduce helper for finding referral server to improve DFS target resolution
Some servers seem to mistakenly report different values for
capabilities and share flags, so we can't always rely on those values
to decide whether the resolved target can handle any new DFS
referrals.

Add a new helper is_referral_server() to check if all resolved targets
can handle new DFS referrals by directly looking at the
GET_DFS_REFERRAL.ReferralHeaderFlags value as specified in MS-DFSC
2.2.4 RESP_GET_DFS_REFERRAL in addition to is_tcon_dfs().

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.11
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-02-25 12:19:15 -06:00
Ronnie Sahlberg 0d4873f9aa cifs: fix dfs domain referrals
The new mount API requires additional changes to how DFS
is handled. Additional testing of DFS uncovered problems
with domain based DFS referrals (a follow on patch addresses
DFS links) which this patch addresses.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-28 21:40:43 -06:00
Tom Rix 77b6ec01c2 cifs: check pointer before freeing
clang static analysis reports this problem

dfs_cache.c:591:2: warning: Argument to kfree() is a constant address
  (18446744073709551614), which is not memory allocated by malloc()
        kfree(vi);
        ^~~~~~~~~

In dfs_cache_del_vol() the volume info pointer 'vi' being freed
is the return of a call to find_vol().  The large constant address
is find_vol() returning an error.

Add an error check to dfs_cache_del_vol() similar to the one done
in dfs_cache_update_vol().

Fixes: 54be1f6c1c ("cifs: Add DFS cache routines")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
CC: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-13 12:55:29 -06:00
Ronnie Sahlberg c741cba2cd cifs: move cifs_cleanup_volume_info[_content] to fs_context.c
and rename it to smb3_cleanup_fs_context[_content]

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:26:30 -06:00
Ronnie Sahlberg 4deb075985 cifs: remove the devname argument to cifs_compose_mount_options
none of the callers use this argument any more.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg 24e0a1eff9 cifs: switch to new mount api
See Documentation/filesystems/mount_api.rst for details on new mount API

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg 837e3a1bbf cifs: rename dup_vol to smb3_fs_context_dup and move it into fs_context.c
Continue restructuring needed for support of new mount API

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg 3fa1c6d1b8 cifs: rename smb_vol as smb3_fs_context and move it to fs_context.h
Harmonize and change all such variables to 'ctx', where possible.
No changes to actual logic.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Linus Torvalds 81e11336d9 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - a few MM hotfixes

 - kthread, tools, scripts, ntfs and ocfs2

 - some of MM

Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  mm: vmscan: consistent update to pgrefill
  mm/vmscan.c: fix typo
  khugepaged: khugepaged_test_exit() check mmget_still_valid()
  khugepaged: retract_page_tables() remember to test exit
  khugepaged: collapse_pte_mapped_thp() protect the pmd lock
  khugepaged: collapse_pte_mapped_thp() flush the right range
  mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
  mm: thp: replace HTTP links with HTTPS ones
  mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
  mm/page_alloc.c: skip setting nodemask when we are in interrupt
  mm/page_alloc: fallbacks at most has 3 elements
  mm/page_alloc: silence a KASAN false positive
  mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
  mm/page_alloc.c: simplify pageblock bitmap access
  mm/page_alloc.c: extract the common part in pfn_to_bitidx()
  mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
  mm/shuffle: remove dynamic reconfiguration
  mm/memory_hotplug: document why shuffle_zone() is relevant
  mm/page_alloc: remove nr_free_pagecache_pages()
  mm: remove vm_total_pages
  ...
2020-08-07 11:39:33 -07:00
Waiman Long 453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00