kernel.git/fs/cifs/file.c, branch linux-4.4.y

cifs: revalidate mapping when we open files for SMB1 POSIX

2021-04-10T11:01:57Z

[ Upstream commit cee8f4f6fcabfdf229542926128e9874d19016d5 ] RHBZ: 1933527 Under SMB1 + POSIX, if an inode is reused on a server after we have read and cached a part of a file, when we then open the new file with the re-cycled inode there is a chance that we may serve the old data out of cache to the application. This only happens for SMB1 (deprecated) and when posix are used. The simplest solution to avoid this race is to force a revalidate on smb1-posix open. Signed-off-by: Ronnie Sahlberg Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French Signed-off-by: Sasha Levin

cifs: Fix null pointer check in cifs_read

2020-06-03T06:12:10Z

[ Upstream commit 9bd21d4b1a767c3abebec203342f3820dcb84662 ] Coverity scan noted a redundant null check Coverity-id: 728517 Reported-by: Coverity Signed-off-by: Steve French Reviewed-by: Shyam Prasad N Signed-off-by: Sasha Levin

CIFS: Respect O_SYNC and O_DIRECT flags during reconnect

2019-12-21T09:35:44Z

commit 44805b0e62f15e90d233485420e1847133716bdc upstream. Currently the client translates O_SYNC and O_DIRECT flags into corresponding SMB create options when openning a file. The problem is that on reconnect when the file is being re-opened the client doesn't set those flags and it causes a server to reject re-open requests because create options don't match. The latter means that any subsequent system call against that open file fail until a share is re-mounted. Fix this by properly setting SMB create options when re-openning files after reconnects. Fixes: 1013e760d10e6: ("SMB3: Don't ignore O_SYNC/O_DSYNC and O_DIRECT flags") Cc: Stable Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman

CIFS: Fix NULL-pointer dereference in smb2_push_mandatory_locks

2019-12-21T09:34:51Z

commit 6f582b273ec23332074d970a7fb25bef835df71f upstream. Currently when the client creates a cifsFileInfo structure for a newly opened file, it allocates a list of byte-range locks with a pointer to the new cfile and attaches this list to the inode's lock list. The latter happens before initializing all other fields, e.g. cfile->tlink. Thus a partially initialized cifsFileInfo structure becomes available to other threads that walk through the inode's lock list. One example of such a thread may be an oplock break worker thread that tries to push all cached byte-range locks. This causes NULL-pointer dereference in smb2_push_mandatory_locks() when accessing cfile->tlink: [598428.945633] BUG: kernel NULL pointer dereference, address: 0000000000000038 ... [598428.945749] Workqueue: cifsoplockd cifs_oplock_break [cifs] [598428.945793] RIP: 0010:smb2_push_mandatory_locks+0xd6/0x5a0 [cifs] ... [598428.945834] Call Trace: [598428.945870] ? cifs_revalidate_mapping+0x45/0x90 [cifs] [598428.945901] cifs_oplock_break+0x13d/0x450 [cifs] [598428.945909] process_one_work+0x1db/0x380 [598428.945914] worker_thread+0x4d/0x400 [598428.945921] kthread+0x104/0x140 [598428.945925] ? process_one_work+0x380/0x380 [598428.945931] ? kthread_park+0x80/0x80 [598428.945937] ret_from_fork+0x35/0x40 Fix this by reordering initialization steps of the cifsFileInfo structure: initialize all the fields first and then add the new byte-range lock list to the inode's lock list. Cc: Stable Signed-off-by: Pavel Shilovsky Reviewed-by: Aurelien Aptel Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman

cifs: Fix cifsInodeInfo lock_sem deadlock when reconnect occurs

2019-11-10T10:21:10Z

[ Upstream commit d46b0da7a33dd8c99d969834f682267a45444ab3 ] There's a deadlock that is possible and can easily be seen with a test where multiple readers open/read/close of the same file and a disruption occurs causing reconnect. The deadlock is due a reader thread inside cifs_strict_readv calling down_read and obtaining lock_sem, and then after reconnect inside cifs_reopen_file calling down_read a second time. If in between the two down_read calls, a down_write comes from another process, deadlock occurs. CPU0 CPU1 ---- ---- cifs_strict_readv() down_read(&cifsi->lock_sem); _cifsFileInfo_put OR cifs_new_fileinfo down_write(&cifsi->lock_sem); cifs_reopen_file() down_read(&cifsi->lock_sem); Fix the above by changing all down_write(lock_sem) calls to down_write_trylock(lock_sem)/msleep() loop, which in turn makes the second down_read call benign since it will never block behind the writer while holding lock_sem. Signed-off-by: Dave Wysochanski Suggested-by: Ronnie Sahlberg Reviewed--by: Ronnie Sahlberg Reviewed-by: Pavel Shilovsky Signed-off-by: Sasha Levin

CIFS: Gracefully handle QueryInfo errors during open

2019-10-17T20:41:03Z

commit 30573a82fb179420b8aac30a3a3595aa96a93156 upstream. Currently if the client identifies problems when processing metadata returned in CREATE response, the open handle is being leaked. This causes multiple problems like a file missing a lease break by that client which causes high latencies to other clients accessing the file. Another side-effect of this is that the file can't be deleted. Fix this by closing the file after the client hits an error after the file was opened and the open descriptor wasn't returned to the user space. Also convert -ESTALE to -EOPENSTALE to allow the VFS to revalidate a dentry and retry the open. Cc: Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman

CIFS: cifs_read_allocate_pages: don't iterate through whole page array on ENOMEM

2019-06-11T10:24:10Z

commit 31fad7d41e73731f05b8053d17078638cf850fa6 upstream. In cifs_read_allocate_pages, in case of ENOMEM, we go through whole rdata->pages array but we have failed the allocation before nr_pages, therefore we may end up calling put_page with NULL pointer, causing oops Signed-off-by: Roberto Bergantinos Corpas Acked-by: Pavel Shilovsky Signed-off-by: Steve French CC: Stable Signed-off-by: Greg Kroah-Hartman

CIFS: fix POSIX lock leak and invalid ptr deref

2019-04-27T07:33:47Z

[ Upstream commit bc31d0cdcfbadb6258b45db97e93b1c83822ba33 ] We have a customer reporting crashes in lock_get_status() with many "Leaked POSIX lock" messages preceeding the crash. Leaked POSIX lock on dev=0x0:0x56 ... Leaked POSIX lock on dev=0x0:0x56 ... Leaked POSIX lock on dev=0x0:0x56 ... Leaked POSIX lock on dev=0x0:0x53 ... Leaked POSIX lock on dev=0x0:0x53 ... Leaked POSIX lock on dev=0x0:0x53 ... Leaked POSIX lock on dev=0x0:0x53 ... POSIX: fl_owner=ffff8900e7b79380 fl_flags=0x1 fl_type=0x1 fl_pid=20709 Leaked POSIX lock on dev=0x0:0x4b ino... Leaked locks on dev=0x0:0x4b ino=0xf911400000029: POSIX: fl_owner=ffff89f41c870e00 fl_flags=0x1 fl_type=0x1 fl_pid=19592 stack segment: 0000 [#1] SMP Modules linked in: binfmt_misc msr tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag rpcsec_gss_krb5 arc4 ecb auth_rpcgss nfsv4 md4 nfs nls_utf8 lockd grace cifs sunrpc ccm dns_resolver fscache af_packet iscsi_ibft iscsi_boot_sysfs vmw_vsock_vmci_transport vsock xfs libcrc32c sb_edac edac_core crct10dif_pclmul crc32_pclmul ghash_clmulni_intel drbg ansi_cprng vmw_balloon aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd joydev pcspkr vmxnet3 i2c_piix4 vmw_vmci shpchp fjes processor button ac btrfs xor raid6_pq sr_mod cdrom ata_generic sd_mod ata_piix vmwgfx crc32c_intel drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm serio_raw ahci libahci drm libata vmw_pvscsi sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: Yes CPU: 6 PID: 28250 Comm: lsof Not tainted 4.4.156-94.64-default #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016 task: ffff88a345f28740 ti: ffff88c74005c000 task.ti: ffff88c74005c000 RIP: 0010:[] [] lock_get_status+0x9b/0x3b0 RSP: 0018:ffff88c74005fd90 EFLAGS: 00010202 RAX: ffff89bde83e20ae RBX: ffff89e870003d18 RCX: 0000000049534f50 RDX: ffffffff81a3541f RSI: ffffffff81a3544e RDI: ffff89bde83e20ae RBP: 0026252423222120 R08: 0000000020584953 R09: 000000000000ffff R10: 0000000000000000 R11: ffff88c74005fc70 R12: ffff89e5ca7b1340 R13: 00000000000050e5 R14: ffff89e870003d30 R15: ffff89e5ca7b1340 FS: 00007fafd64be800(0000) GS:ffff89f41fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001c80018 CR3: 000000a522048000 CR4: 0000000000360670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 0000000000000208 ffffffff81a3d6b6 ffff89e870003d30 ffff89e870003d18 ffff89e5ca7b1340 ffff89f41738d7c0 ffff89e870003d30 ffff89e5ca7b1340 ffffffff8125e08f 0000000000000000 ffff89bc22b67d00 ffff88c74005ff28 Call Trace: [] locks_show+0x2f/0x70 [] seq_read+0x251/0x3a0 [] proc_reg_read+0x3c/0x70 [] __vfs_read+0x26/0x140 [] vfs_read+0x7a/0x120 [] SyS_read+0x42/0xa0 [] entry_SYSCALL_64_fastpath+0x1e/0xb7 When Linux closes a FD (close(), close-on-exec, dup2(), ...) it calls filp_close() which also removes all posix locks. The lock struct is initialized like so in filp_close() and passed down to cifs ... lock.fl_type = F_UNLCK; lock.fl_flags = FL_POSIX | FL_CLOSE; lock.fl_start = 0; lock.fl_end = OFFSET_MAX; ... Note the FL_CLOSE flag, which hints the VFS code that this unlocking is done for closing the fd. filp_close() locks_remove_posix(filp, id); vfs_lock_file(filp, F_SETLK, &lock, NULL); return filp->f_op->lock(filp, cmd, fl) => cifs_lock() rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock, xid); rc = server->ops->mand_unlock_range(cfile, flock, xid); if (flock->fl_flags & FL_POSIX && !rc) rc = locks_lock_file_wait(file, flock) Notice how we don't call locks_lock_file_wait() which does the generic VFS lock/unlock/wait work on the inode if rc != 0. If we are closing the handle, the SMB server is supposed to remove any locks associated with it. Similarly, cifs.ko frees and wakes up any lock and lock waiter when closing the file: cifs_close() cifsFileInfo_put(file->private_data) /* * Delete any outstanding lock records. We'll lose them when the file * is closed anyway. */ down_write(&cifsi->lock_sem); list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) { list_del(&li->llist); cifs_del_lock_waiters(li); kfree(li); } list_del(&cifs_file->llist->llist); kfree(cifs_file->llist); up_write(&cifsi->lock_sem); So we can safely ignore unlocking failures in cifs_lock() if they happen with the FL_CLOSE flag hint set as both the server and the client take care of it during the actual closing. This is not a proper fix for the unlocking failure but it's safe and it seems to prevent the lock leakages and crashes the customer experiences. Signed-off-by: Aurelien Aptel Signed-off-by: NeilBrown Signed-off-by: Steve French Acked-by: Pavel Shilovsky Signed-off-by: Sasha Levin

CIFS: Fix read after write for files with read caching

2019-03-23T07:44:35Z

commit 6dfbd84684700cb58b34e8602c01c12f3d2595c8 upstream. When we have a READ lease for a file and have just issued a write operation to the server we need to purge the cache and set oplock/lease level to NONE to avoid reading stale data. Currently we do that only if a write operation succedeed thus not covering cases when a request was sent to the server but a negative error code was returned later for some other reasons (e.g. -EIOCBQUEUED or -EINTR). Fix this by turning off caching regardless of the error code being returned. The patches fixes generic tests 075 and 112 from the xfs-tests. Cc: Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French Reviewed-by: Ronnie Sahlberg Signed-off-by: Greg Kroah-Hartman

cifs: Limit memory used by lock request calls to a page

2019-02-20T09:13:21Z

[ Upstream commit 92a8109e4d3a34fb6b115c9098b51767dc933444 ] The code tries to allocate a contiguous buffer with a size supplied by the server (maxBuf). This could fail if memory is fragmented since it results in high order allocations for commonly used server implementations. It is also wasteful since there are probably few locks in the usual case. Limit the buffer to be no larger than a page to avoid memory allocation failures due to fragmentation. Signed-off-by: Ross Lagerwall Signed-off-by: Steve French Signed-off-by: Sasha Levin