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path: root/fs/cifs/smb2misc.c
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2020-12-14cifs: remove various function description warningsSteve French
When compiling with W=1 I noticed various functions that did not follow proper style in describing (in the comments) the parameters passed in to the function. For example: fs/cifs/inode.c:2236: warning: Function parameter or member 'mode' not described in 'cifs_wait_bit_killable' I did not address the style warnings in two of the six files (connect.c and misc.c) in order to reduce risk of merge conflict with pending patches. We can update those later. Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13SMB3.1.1: update comments clarifying SPNEGO info in negprot responseSteve French
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>
2020-12-13SMB3.1.1: remove confusing mount warning when no SPNEGO info on negprot rspSteve French
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>
2020-08-02cifs: Fix leak when handling lease break for cached root fidPaul Aurich
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: a93864d93977 ("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>
2020-07-08smb3: fix unneeded error message on change notifySteve French
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>
2020-06-01cifs: Standardize logging outputJoe Perches
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>
2020-04-07cifs: ignore cached share root handle closing errorsAurelien Aptel
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: d9191319358d ("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>
2020-01-26cifs: Fix memory allocation in __smb2_handle_cancelled_cmd()Paulo Alcantara (SUSE)
__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: 9150c3adbf24 ("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>
2019-11-25CIFS: Properly process SMB3 lease breaksPavel Shilovsky
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>
2019-11-25cifs: try opening channels after mountingAurelien Aptel
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>
2019-11-25CIFS: Fix SMB2 oplock break processingPavel Shilovsky
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>
2019-11-25smb3: add debug messages for closing unmatched openRonnie Sahlberg
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>
2019-11-25CIFS: Close open handle after interrupted closePavel Shilovsky
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>
2019-11-25smb3: remove confusing dmesg when mounting with encryption ("seal")Steve French
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>
2019-04-16CIFS: keep FileInfo handle live during oplock breakAurelien Aptel
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>
2019-03-04CIFS: Do not reset lease state to NONE on lease breakPavel Shilovsky
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 c11f1df5003d534 ("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>
2019-03-04cifs: add credits from unmatched responses/messagesRonnie Sahlberg
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>
2019-01-24smb3: add credits we receive from oplock/break PDUsRonnie Sahlberg
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>
2018-09-02smb3: minor debugging clarifications in rfc1001 len processingSteve French
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>
2018-08-23cifs: check if SMB2 PDU size has been padded and suppress the warningRonnie Sahlberg
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>
2018-08-07smb3: simplify code by removing CONFIG_CIFS_SMB311Steve French
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>
2018-06-15smb3: fix corrupt path in subdirs on smb311 with posixSteve French
Signed-off-by: Steve French <stfrench@microsoft.com>
2018-06-15cifs: add lease tracking to the cached root fidRonnie Sahlberg
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>
2018-06-07CIFS: Fix NULL ptr derefAurelien Aptel
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>
2018-06-02cifs: update multiplex loop to handle compounded responsesRonnie Sahlberg
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
2018-06-01cifs: remove header_preamble_size where it is always 0Ronnie Sahlberg
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>
2018-06-01cifs: remove struct smb2_hdrRonnie Sahlberg
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>
2018-05-31cifs: change smb2_get_data_area_len to take a smb2_sync_hdr as argumentRonnie Sahlberg
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-31cifs: update smb2_calc_size to use smb2_sync_hdr instead of smb2_hdrRonnie Sahlberg
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>
2018-05-31cifs: remove struct smb2_oplock_break_rspRonnie Sahlberg
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>
2018-05-31smb3: Add posix create context for smb3.11 posix mountsSteve French
Signed-off-by: Steve French <smfrench@gmail.com>
2018-05-30cifs: update smb2_check_message to handle PDUs without a 4 byte length headerRonnie Sahlberg
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2018-05-27cifs: update calc_size to take a server argumentRonnie Sahlberg
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>
2018-04-12smb3.11: replace a 4 with server->vals->header_preamble_sizeSteve French
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>
2018-04-12SMB3: Fix length checking of SMB3.11 negotiate requestSteve French
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>
2018-04-02cifs: fix sparse warning on previous patch in a few printksSteve French
Signed-off-by: Steve French <smfrench@gmail.com> CC: Ronnie Sahlberg <lsahlber@redhat.com>
2018-04-02cifs: add server->vals->header_preamble_sizeRonnie Sahlberg
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>
2018-04-01CIFS: implement v3.11 preauth integrityAurelien Aptel
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>
2018-01-24cifs: remove rfc1002 header from smb2_oplock_break we get from serverRonnie Sahlberg
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>
2017-05-03CIFS: fix oplock break deadlocksRabin Vincent
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>
2017-04-07Handle mismatched open callsSachin Prabhu
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>
2017-02-01CIFS: Separate SMB2 header structurePavel Shilovsky
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>
2016-10-12Clarify locking of cifs file and tcon structures and make more granularSteve French
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>
2016-01-14Prepare for encryption support (first part). Add decryption and encryption ↵Steve French
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>
2015-04-15VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells
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>
2015-04-01Fix coverity warningSteve French
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>
2014-12-14Convert MessageID in smb2_hdr to LESachin Prabhu
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>
2014-12-10fs/cifs: remove obsolete __constantFabian Frederick
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>
2014-10-16Allow conversion of characters in Mac remap range (part 2)Steve French
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>
2014-08-15[CIFS] Workaround MacOS server problem with SMB2.1 writeSteve French
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>
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