Commit Graph

71 Commits

Author SHA1 Message Date
Steve French
145024e3e4 SMB3.1.1: update comments clarifying SPNEGO info in negprot response
Trivial changes to clarify confusing comment about
SPNEGO blog (and also one length comparisons in negotiate
context parsing).

Suggested-by: Tom Talpey <tom@talpey.com>
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Steve French
bc7c4129d4 SMB3.1.1: remove confusing mount warning when no SPNEGO info on negprot rsp
Azure does not send an SPNEGO blob in the negotiate protocol response,
so we shouldn't assume that it is there when validating the location
of the first negotiate context.  This avoids the potential confusing
mount warning:

   CIFS: Invalid negotiate context offset

CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Paul Aurich
baf57b56d3 cifs: Fix leak when handling lease break for cached root fid
Handling a lease break for the cached root didn't free the
smb2_lease_break_work allocation, resulting in a leak:

    unreferenced object 0xffff98383a5af480 (size 128):
      comm "cifsd", pid 684, jiffies 4294936606 (age 534.868s)
      hex dump (first 32 bytes):
        c0 ff ff ff 1f 00 00 00 88 f4 5a 3a 38 98 ff ff  ..........Z:8...
        88 f4 5a 3a 38 98 ff ff 80 88 d6 8a ff ff ff ff  ..Z:8...........
      backtrace:
        [<0000000068957336>] smb2_is_valid_oplock_break+0x1fa/0x8c0
        [<0000000073b70b9e>] cifs_demultiplex_thread+0x73d/0xcc0
        [<00000000905fa372>] kthread+0x11c/0x150
        [<0000000079378e4e>] ret_from_fork+0x22/0x30

Avoid this leak by only allocating when necessary.

Fixes: a93864d939 ("cifs: add lease tracking to the cached root fid")
Signed-off-by: Paul Aurich <paul@darkrain42.org>
CC: Stable <stable@vger.kernel.org> # v4.18+
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-02 18:00:25 -05:00
Steve French
8668115cf2 smb3: fix unneeded error message on change notify
We should not be logging a warning repeatedly on change notify.

CC: Stable <stable@vger.kernel.org> # v5.6+
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-07-08 03:59:02 -05:00
Joe Perches
a0a3036b81 cifs: Standardize logging output
Use pr_fmt to standardize all logging for fs/cifs.

Some logging output had no CIFS: specific prefix.

Now all output has one of three prefixes:

o CIFS:
o CIFS: VFS:
o Root-CIFS:

Miscellanea:

o Convert printks to pr_<level>
o Neaten macro definitions
o Remove embedded CIFS: prefixes from formats
o Convert "illegal" to "invalid"
o Coalesce formats
o Add missing '\n' format terminations
o Consolidate multiple cifs_dbg continuations into single calls
o More consistent use of upper case first word output logging
o Multiline statement argument alignment and wrapping

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Aurelien Aptel
e79b0332ae cifs: ignore cached share root handle closing errors
Fix tcon use-after-free and NULL ptr deref.

Customer system crashes with the following kernel log:

[462233.169868] CIFS VFS: Cancelling wait for mid 4894753 cmd: 14       => a QUERY DIR
[462233.228045] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4
[462233.305922] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4
[462233.306205] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4
[462233.347060] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4
[462233.347107] CIFS VFS: Close unmatched open
[462233.347113] BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
...
    [exception RIP: cifs_put_tcon+0xa0] (this is doing tcon->ses->server)
 #6 [...] smb2_cancelled_close_fid at ... [cifs]
 #7 [...] process_one_work at ...
 #8 [...] worker_thread at ...
 #9 [...] kthread at ...

The most likely explanation we have is:

* When we put the last reference of a tcon (refcount=0), we close the
  cached share root handle.
* If closing a handle is interrupted, SMB2_close() will
  queue a SMB2_close() in a work thread.
* The queued object keeps a tcon ref so we bump the tcon
  refcount, jumping from 0 to 1.
* We reach the end of cifs_put_tcon(), we free the tcon object despite
  it now having a refcount of 1.
* The queued work now runs, but the tcon, ses & server was freed in
  the meantime resulting in a crash.

THREAD 1
========
cifs_put_tcon                 => tcon refcount reach 0
  SMB2_tdis
   close_shroot_lease
    close_shroot_lease_locked => if cached root has lease && refcount = 0
     smb2_close_cached_fid    => if cached root valid
      SMB2_close              => retry close in a thread if interrupted
       smb2_handle_cancelled_close
        __smb2_handle_cancelled_close    => !! tcon refcount bump 0 => 1 !!
         INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
         queue_work(cifsiod_wq, &cancelled->work) => queue work
 tconInfoFree(tcon);    ==> freed!
 cifs_put_smb_ses(ses); ==> freed!

THREAD 2 (workqueue)
========
smb2_cancelled_close_fid
  SMB2_close(0, cancelled->tcon, ...); => use-after-free of tcon
  cifs_put_tcon(cancelled->tcon);      => tcon refcount reach 0 second time
  *CRASH*

Fixes: d919131935 ("CIFS: Close cached root handle only if it has a lease")
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-04-07 12:40:40 -05:00
Paulo Alcantara (SUSE)
0a5a98863c cifs: Fix memory allocation in __smb2_handle_cancelled_cmd()
__smb2_handle_cancelled_cmd() is called under a spin lock held in
cifs_mid_q_entry_release(), so make its memory allocation GFP_ATOMIC.

This issue was observed when running xfstests generic/028:

[ 1722.589204] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72064 cmd: 5
[ 1722.590687] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72065 cmd: 17
[ 1722.593529] CIFS VFS: \\192.168.30.26 Cancelling wait for mid 72066 cmd: 6
[ 1723.039014] BUG: sleeping function called from invalid context at mm/slab.h:565
[ 1723.040710] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 30877, name: cifsd
[ 1723.045098] CPU: 3 PID: 30877 Comm: cifsd Not tainted 5.5.0-rc4+ #313
[ 1723.046256] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
[ 1723.048221] Call Trace:
[ 1723.048689]  dump_stack+0x97/0xe0
[ 1723.049268]  ___might_sleep.cold+0xd1/0xe1
[ 1723.050069]  kmem_cache_alloc_trace+0x204/0x2b0
[ 1723.051051]  __smb2_handle_cancelled_cmd+0x40/0x140 [cifs]
[ 1723.052137]  smb2_handle_cancelled_mid+0xf6/0x120 [cifs]
[ 1723.053247]  cifs_mid_q_entry_release+0x44d/0x630 [cifs]
[ 1723.054351]  ? cifs_reconnect+0x26a/0x1620 [cifs]
[ 1723.055325]  cifs_demultiplex_thread+0xad4/0x14a0 [cifs]
[ 1723.056458]  ? cifs_handle_standard+0x2c0/0x2c0 [cifs]
[ 1723.057365]  ? kvm_sched_clock_read+0x14/0x30
[ 1723.058197]  ? sched_clock+0x5/0x10
[ 1723.058838]  ? sched_clock_cpu+0x18/0x110
[ 1723.059629]  ? lockdep_hardirqs_on+0x17d/0x250
[ 1723.060456]  kthread+0x1ab/0x200
[ 1723.061149]  ? cifs_handle_standard+0x2c0/0x2c0 [cifs]
[ 1723.062078]  ? kthread_create_on_node+0xd0/0xd0
[ 1723.062897]  ret_from_fork+0x3a/0x50

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Fixes: 9150c3adbf ("CIFS: Close open handle after interrupted close")
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-01-26 19:24:17 -06:00
Pavel Shilovsky
9bd4540836 CIFS: Properly process SMB3 lease breaks
Currenly we doesn't assume that a server may break a lease
from RWH to RW which causes us setting a wrong lease state
on a file and thus mistakenly flushing data and byte-range
locks and purging cached data on the client. This leads to
performance degradation because subsequent IOs go directly
to the server.

Fix this by propagating new lease state and epoch values
to the oplock break handler through cifsFileInfo structure
and removing the use of cifsInodeInfo flags for that. It
allows to avoid some races of several lease/oplock breaks
using those flags in parallel.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:17:12 -06:00
Aurelien Aptel
d70e9fa558 cifs: try opening channels after mounting
After doing mount() successfully we call cifs_try_adding_channels()
which will open as many channels as it can.

Channels are closed when the master session is closed.

The master connection becomes the first channel.

,-------------> global cifs_tcp_ses_list <-------------------------.
|                                                                  |
'- TCP_Server_Info  <-->  TCP_Server_Info  <-->  TCP_Server_Info <-'
      (master con)           (chan#1 con)         (chan#2 con)
      |      ^                    ^                    ^
      v      '--------------------|--------------------'
   cifs_ses                       |
   - chan_count = 3               |
   - chans[] ---------------------'
   - smb3signingkey[]
      (master signing key)

Note how channel connections don't have sessions. That's because
cifs_ses can only be part of one linked list (list_head are internal
to the elements).

For signing keys, each channel has its own signing key which must be
used only after the channel has been bound. While it's binding it must
use the master session signing key.

For encryption keys, since channel connections do not have sessions
attached we must now find matching session by looping over all sessions
in smb2_get_enc_key().

Each channel is opened like a regular server connection but at the
session setup request step it must set the
SMB2_SESSION_REQ_FLAG_BINDING flag and use the session id to bind to.

Finally, while sending in compound_send_recv() for requests that
aren't negprot, ses-setup or binding related, use a channel by cycling
through the available ones (round-robin).

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Pavel Shilovsky
fa9c236249 CIFS: Fix SMB2 oplock break processing
Even when mounting modern protocol version the server may be
configured without supporting SMB2.1 leases and the client
uses SMB2 oplock to optimize IO performance through local caching.

However there is a problem in oplock break handling that leads
to missing a break notification on the client who has a file
opened. It latter causes big latencies to other clients that
are trying to open the same file.

The problem reproduces when there are multiple shares from the
same server mounted on the client. The processing code tries to
match persistent and volatile file ids from the break notification
with an open file but it skips all share besides the first one.
Fix this by looking up in all shares belonging to the server that
issued the oplock break.

Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Ronnie Sahlberg
87bc2376ff smb3: add debug messages for closing unmatched open
Helps distinguish between an interrupted close and a truly
unmatched open.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:14:53 -06:00
Pavel Shilovsky
9150c3adbf CIFS: Close open handle after interrupted close
If Close command is interrupted before sending a request
to the server the client ends up leaking an open file
handle. This wastes server resources and can potentially
block applications that try to remove the file or any
directory containing this file.

Fix this by putting the close command into a worker queue,
so another thread retries it later.

Cc: Stable <stable@vger.kernel.org>
Tested-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:14:53 -06:00
Steve French
037d050724 smb3: remove confusing dmesg when mounting with encryption ("seal")
The smb2/smb3 message checking code was logging to dmesg when mounting
with encryption ("seal") for compounded SMB3 requests.  When encrypted
the whole frame (including potentially multiple compounds) is read
so the length field is longer than in the case of non-encrypted
case (where length field will match the the calculated length for
the particular SMB3 request in the compound being validated).

Avoids the warning on mount (with "seal"):

   "srv rsp padded more than expected. Length 384 not ..."

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:14:53 -06:00
Aurelien Aptel
b98749cac4 CIFS: keep FileInfo handle live during oplock break
In the oplock break handler, writing pending changes from pages puts
the FileInfo handle. If the refcount reaches zero it closes the handle
and waits for any oplock break handler to return, thus causing a deadlock.

To prevent this situation:

* We add a wait flag to cifsFileInfo_put() to decide whether we should
  wait for running/pending oplock break handlers

* We keep an additionnal reference of the SMB FileInfo handle so that
  for the rest of the handler putting the handle won't close it.
  - The ref is bumped everytime we queue the handler via the
    cifs_queue_oplock_break() helper.
  - The ref is decremented at the end of the handler

This bug was triggered by xfstest 464.

Also important fix to address the various reports of
oops in smb2_push_mandatory_locks

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2019-04-16 09:38:38 -05:00
Pavel Shilovsky
7b9b9edb49 CIFS: Do not reset lease state to NONE on lease break
Currently on lease break the client sets a caching level twice:
when oplock is detected and when oplock is processed. While the
1st attempt sets the level to the value provided by the server,
the 2nd one resets the level to None unconditionally.
This happens because the oplock/lease processing code was changed
to avoid races between page cache flushes and oplock breaks.
The commit c11f1df500 ("cifs: Wait for writebacks to complete
before attempting write.") fixed the races for oplocks but didn't
apply the same changes for leases resulting in overwriting the
server granted value to None. Fix this by properly processing
lease breaks.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2019-03-04 20:05:35 -06:00
Ronnie Sahlberg
eca0045238 cifs: add credits from unmatched responses/messages
We should add any credits granted to us from unmatched server responses.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-04 20:05:34 -06:00
Ronnie Sahlberg
2e5700bdde smb3: add credits we receive from oplock/break PDUs
Otherwise we gradually leak credits leading to potential
hung session.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-01-24 14:52:06 -06:00
Steve French
25f2573512 smb3: minor debugging clarifications in rfc1001 len processing
I ran into some cases where server was returning the wrong length
on frames but I couldn't easily match them to the command in the
network trace (or server logs) since I need the command and/or
multiplex id to find the offending SMB2/SMB3 command.  Add these
two fields to the log message. In the case of padding too much
it may not be a problem in all cases but might have correlated
to a network disconnect case in some problems we have been
looking at. In the case of frame too short is even more important.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-09-02 23:21:42 -05:00
Ronnie Sahlberg
e6c47dd0da cifs: check if SMB2 PDU size has been padded and suppress the warning
Some SMB2/3 servers, Win2016 but possibly others too, adds padding
not only between PDUs in a compound but also to the final PDU.
This padding extends the PDU to a multiple of 8 bytes.

Check if the unexpected length looks like this might be the case
and avoid triggering the log messages for :

  "SMB2 server sent bad RFC1001 len %d not %d\n"

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-08-23 15:10:46 -05:00
Steve French
0fdfef9aa7 smb3: simplify code by removing CONFIG_CIFS_SMB311
We really, really want to be encouraging use of secure dialects,
and SMB3.1.1 offers useful security features, and will soon
be the recommended dialect for many use cases. Simplify the code
by removing the CONFIG_CIFS_SMB311 ifdef so users don't disable
it in the build, and create compatibility and/or security issues
with modern servers - many of which have been supporting this
dialect for multiple years.

Also clarify some of the Kconfig text for cifs.ko about
SMB3.1.1 and current supported features in the module.

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-08-07 14:15:56 -05:00
Steve French
d819d298c7 smb3: fix corrupt path in subdirs on smb311 with posix
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-15 02:38:08 -05:00
Ronnie Sahlberg
a93864d939 cifs: add lease tracking to the cached root fid
Use a read lease for the cached root fid so that we can detect
when the content of the directory changes (via a break) at which time
we close the handle. On next access to the root the handle will be reopened
and cached again.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-15 02:38:07 -05:00
Aurelien Aptel
8ddecf5fd7 CIFS: Fix NULL ptr deref
cifs->master_tlink is NULL against Win Server 2016 (which is
strange.. not sure why) and is dereferenced in cifs_sb_master_tcon().

move master_tlink getter to cifsglob.h so it can be used from
smb2misc.c

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-06-07 08:31:31 -05:00
Ronnie Sahlberg
8ce79ec359 cifs: update multiplex loop to handle compounded responses
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2018-06-02 18:36:26 -05:00
Ronnie Sahlberg
1fc6ad2f10 cifs: remove header_preamble_size where it is always 0
Since header_preamble_size is 0 for SMB2+ we can remove it in those
code paths that are only invoked from SMB2.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-01 09:14:30 -05:00
Ronnie Sahlberg
49f466bdbd cifs: remove struct smb2_hdr
struct smb2_hdr is now just a wrapper for smb2_sync_hdr.
We can thus get rid of smb2_hdr completely and access the sync header directly.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-01 09:14:30 -05:00
Ronnie Sahlberg
e4dc31fe9a cifs: change smb2_get_data_area_len to take a smb2_sync_hdr as argument
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-31 21:30:51 -05:00
Ronnie Sahlberg
84f0cbfba8 cifs: update smb2_calc_size to use smb2_sync_hdr instead of smb2_hdr
smb2_hdr is just a wrapper around smb2_sync_hdr at this stage
and smb2_hdr is going away.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-31 21:30:51 -05:00
Ronnie Sahlberg
0d5a288d25 cifs: remove struct smb2_oplock_break_rsp
The two structures smb2_oplock_breaq_req/rsp are now basically identical.
Replace this with a single definition of a smb2_oplock_break structure.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-31 21:30:51 -05:00
Steve French
ce558b0e17 smb3: Add posix create context for smb3.11 posix mounts
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-31 21:23:07 -05:00
Ronnie Sahlberg
98170fb535 cifs: update smb2_check_message to handle PDUs without a 4 byte length header
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-30 17:24:14 -05:00
Ronnie Sahlberg
9ec672bd17 cifs: update calc_size to take a server argument
and change the smb2 version to take heder_preamble_size into account
instead of hardcoding it as 4 bytes.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-27 17:56:35 -05:00
Steve French
0d4b46ba7d smb3.11: replace a 4 with server->vals->header_preamble_size
More cleanup of use of hardcoded 4 byte RFC1001 field size

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-04-12 20:32:13 -05:00
Steve French
136ff1b4b6 SMB3: Fix length checking of SMB3.11 negotiate request
The length checking for SMB3.11 negotiate request includes
"negotiate contexts" which caused a buffer validation problem
and a confusing warning message on SMB3.11 mount e.g.:

     SMB2 server sent bad RFC1001 len 236 not 170

Fix the length checking for SMB3.11 negotiate to account for
the new negotiate context so that we don't log a warning on
SMB3.11 mount by default but do log warnings if lengths returned
by the server are incorrect.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-04-12 16:52:38 -05:00
Steve French
6c4ba31133 cifs: fix sparse warning on previous patch in a few printks
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Ronnie Sahlberg <lsahlber@redhat.com>
2018-04-02 13:10:40 -05:00
Ronnie Sahlberg
93012bf984 cifs: add server->vals->header_preamble_size
This variable is set to 4 for all protocol versions and replaces
the hardcoded constant 4 throughought the code.
This will later be updated to reflect whether a response packet
has a 4 byte length preamble or not once we start removing this
field from the SMB2+ dialects.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-04-02 13:09:44 -05:00
Aurelien Aptel
8bd68c6e47 CIFS: implement v3.11 preauth integrity
SMB3.11 clients must implement pre-authentification integrity.

* new mechanism to certify requests/responses happening before Tree
  Connect.
* supersedes VALIDATE_NEGOTIATE
* fixes signing for SMB3.11

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-04-01 20:24:40 -05:00
Ronnie Sahlberg
21ad9487ca cifs: remove rfc1002 header from smb2_oplock_break we get from server
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2018-01-24 19:49:05 -06:00
Rabin Vincent
3998e6b87d CIFS: fix oplock break deadlocks
When the final cifsFileInfo_put() is called from cifsiod and an oplock
break work is queued, lockdep complains loudly:

 =============================================
 [ INFO: possible recursive locking detected ]
 4.11.0+ #21 Not tainted
 ---------------------------------------------
 kworker/0:2/78 is trying to acquire lock:
  ("cifsiod"){++++.+}, at: flush_work+0x215/0x350

 but task is already holding lock:
  ("cifsiod"){++++.+}, at: process_one_work+0x255/0x8e0

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock("cifsiod");
   lock("cifsiod");

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 2 locks held by kworker/0:2/78:
  #0:  ("cifsiod"){++++.+}, at: process_one_work+0x255/0x8e0
  #1:  ((&wdata->work)){+.+...}, at: process_one_work+0x255/0x8e0

 stack backtrace:
 CPU: 0 PID: 78 Comm: kworker/0:2 Not tainted 4.11.0+ #21
 Workqueue: cifsiod cifs_writev_complete
 Call Trace:
  dump_stack+0x85/0xc2
  __lock_acquire+0x17dd/0x2260
  ? match_held_lock+0x20/0x2b0
  ? trace_hardirqs_off_caller+0x86/0x130
  ? mark_lock+0xa6/0x920
  lock_acquire+0xcc/0x260
  ? lock_acquire+0xcc/0x260
  ? flush_work+0x215/0x350
  flush_work+0x236/0x350
  ? flush_work+0x215/0x350
  ? destroy_worker+0x170/0x170
  __cancel_work_timer+0x17d/0x210
  ? ___preempt_schedule+0x16/0x18
  cancel_work_sync+0x10/0x20
  cifsFileInfo_put+0x338/0x7f0
  cifs_writedata_release+0x2a/0x40
  ? cifs_writedata_release+0x2a/0x40
  cifs_writev_complete+0x29d/0x850
  ? preempt_count_sub+0x18/0xd0
  process_one_work+0x304/0x8e0
  worker_thread+0x9b/0x6a0
  kthread+0x1b2/0x200
  ? process_one_work+0x8e0/0x8e0
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x31/0x40

This is a real warning.  Since the oplock is queued on the same
workqueue this can deadlock if there is only one worker thread active
for the workqueue (which will be the case during memory pressure when
the rescuer thread is handling it).

Furthermore, there is at least one other kind of hang possible due to
the oplock break handling if there is only worker.  (This can be
reproduced without introducing memory pressure by having passing 1 for
the max_active parameter of cifsiod.) cifs_oplock_break() can wait
indefintely in the filemap_fdatawait() while the cifs_writev_complete()
work is blocked:

 sysrq: SysRq : Show Blocked State
   task                        PC stack   pid father
 kworker/0:1     D    0    16      2 0x00000000
 Workqueue: cifsiod cifs_oplock_break
 Call Trace:
  __schedule+0x562/0xf40
  ? mark_held_locks+0x4a/0xb0
  schedule+0x57/0xe0
  io_schedule+0x21/0x50
  wait_on_page_bit+0x143/0x190
  ? add_to_page_cache_lru+0x150/0x150
  __filemap_fdatawait_range+0x134/0x190
  ? do_writepages+0x51/0x70
  filemap_fdatawait_range+0x14/0x30
  filemap_fdatawait+0x3b/0x40
  cifs_oplock_break+0x651/0x710
  ? preempt_count_sub+0x18/0xd0
  process_one_work+0x304/0x8e0
  worker_thread+0x9b/0x6a0
  kthread+0x1b2/0x200
  ? process_one_work+0x8e0/0x8e0
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x31/0x40
 dd              D    0   683    171 0x00000000
 Call Trace:
  __schedule+0x562/0xf40
  ? mark_held_locks+0x29/0xb0
  schedule+0x57/0xe0
  io_schedule+0x21/0x50
  wait_on_page_bit+0x143/0x190
  ? add_to_page_cache_lru+0x150/0x150
  __filemap_fdatawait_range+0x134/0x190
  ? do_writepages+0x51/0x70
  filemap_fdatawait_range+0x14/0x30
  filemap_fdatawait+0x3b/0x40
  filemap_write_and_wait+0x4e/0x70
  cifs_flush+0x6a/0xb0
  filp_close+0x52/0xa0
  __close_fd+0xdc/0x150
  SyS_close+0x33/0x60
  entry_SYSCALL_64_fastpath+0x1f/0xbe

 Showing all locks held in the system:
 2 locks held by kworker/0:1/16:
  #0:  ("cifsiod"){.+.+.+}, at: process_one_work+0x255/0x8e0
  #1:  ((&cfile->oplock_break)){+.+.+.}, at: process_one_work+0x255/0x8e0

 Showing busy workqueues and worker pools:
 workqueue cifsiod: flags=0xc
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1
     in-flight: 16:cifs_oplock_break
     delayed: cifs_writev_complete, cifs_echo_request
 pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=0s workers=3 idle: 750 3

Fix these problems by creating a a new workqueue (with a rescuer) for
the oplock break work.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
2017-05-03 10:10:10 -05:00
Sachin Prabhu
38bd49064a Handle mismatched open calls
A signal can interrupt a SendReceive call which result in incoming
responses to the call being ignored. This is a problem for calls such as
open which results in the successful response being ignored. This
results in an open file resource on the server.

The patch looks into responses which were cancelled after being sent and
in case of successful open closes the open fids.

For this patch, the check is only done in SendReceive2()

RH-bz: 1403319

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Cc: Stable <stable@vger.kernel.org>
2017-04-07 08:04:40 -05:00
Pavel Shilovsky
31473fc4f9 CIFS: Separate SMB2 header structure
In order to support compounding and encryption we need to separate
RFC1001 length field and SMB2 header structure because the protocol
treats them differently. This change will allow to simplify parsing
of such complex SMB2 packets further.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-02-01 16:46:34 -06:00
Steve French
3afca265b5 Clarify locking of cifs file and tcon structures and make more granular
Remove the global file_list_lock to simplify cifs/smb3 locking and
have spinlocks that more closely match the information they are
protecting.

Add new tcon->open_file_lock and file->file_info_lock spinlocks.
Locks continue to follow a heirachy,
	cifs_socket --> cifs_ses --> cifs_tcon --> cifs_file
where global tcp_ses_lock still protects socket and cifs_ses, while the
the newer locks protect the lower level structure's information
(tcon and cifs_file respectively).

CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
2016-10-12 12:08:32 -05:00
Steve French
373512ec5c Prepare for encryption support (first part). Add decryption and encryption key generation. Thanks to Metze for helping with this.
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
2016-01-14 14:29:42 -06:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Steve French
064bcc0702 Fix coverity warning
Coverity reports a warning for referencing the beginning of the
SMB2/SMB3 frame using the ProtocolId field as an array. Although
it works the same either way, this patch should quiet the warning
and might be a little clearer.

Reported by Coverity (CID 741269)

Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
2015-04-01 00:01:47 -05:00
Sachin Prabhu
9235d09873 Convert MessageID in smb2_hdr to LE
We have encountered failures when When testing smb2 mounts on ppc64
machines when using both Samba as well as Windows 2012.

On poking around, the problem was determined to be caused by the
high endian MessageID passed in the header for smb2. On checking the
corresponding MID for smb1 is converted to LE before being sent on the
wire.

We have tested this patch successfully on a ppc64 machine.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
2014-12-14 14:55:45 -06:00
Fabian Frederick
bc09d141eb fs/cifs: remove obsolete __constant
Replace all __constant_foo to foo() except in smb2status.h (1700 lines to
update).

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Steve French <sfrench@samba.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:02 -08:00
Steve French
a4153cb1d3 Allow conversion of characters in Mac remap range (part 2)
The previous patch allowed remapping reserved characters from directory
listenings, this patch adds conversion the other direction, allowing
opening of files with any of the seven reserved characters.

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
2014-10-16 15:20:20 -05:00
Steve French
754789a1c0 [CIFS] Workaround MacOS server problem with SMB2.1 write
response

Writes fail to Mac servers with SMB2.1 mounts (works with cifs though) due
to them sending an incorrect RFC1001 length for the SMB2.1 Write response.
Workaround this problem. MacOS server sends a write response with 3 bytes
of pad beyond the end of the SMB itself.  The RFC1001 length is 3 bytes
more than the sum of the SMB2.1 header length + the write reponse.

Incorporate feedback from Jeff and JRA to allow servers to send
a tcp frame that is even more than three bytes too long
(ie much longer than the SMB2/SMB3 request that it contains) but
we do log it once now. In the earlier version of the patch I had
limited how far off the length field could be before we fail the request.

Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-15 23:49:01 -05:00
Steve French
59b04c5df7 [CIFS] Fix incorrect hex vs. decimal in some debug print statements
Joe Perches and Hans Wennborg noticed that various places in the
kernel were printing decimal numbers with 0x prefix.
    printk("0x%d") or equivalent
This fixes the instances of this in the cifs driver.

CC: Hans Wennborg <hans@hanshq.net>
CC: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2014-08-02 21:16:48 -05:00