linux/fs
Jeff Layton ea702b80e0 cifs: move check for NULL socket into smb_send_rqst
Cai reported this oops:

[90701.616664] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
[90701.625438] IP: [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.632167] PGD fea319067 PUD 103fda4067 PMD 0
[90701.637255] Oops: 0000 [#1] SMP
[90701.640878] Modules linked in: des_generic md4 nls_utf8 cifs dns_resolver binfmt_misc tun sg igb iTCO_wdt iTCO_vendor_support lpc_ich pcspkr i2c_i801 i2c_core i7core_edac edac_core ioatdma dca mfd_core coretemp kvm_intel kvm crc32c_intel microcode sr_mod cdrom ata_generic sd_mod pata_acpi crc_t10dif ata_piix libata megaraid_sas dm_mirror dm_region_hash dm_log dm_mod
[90701.677655] CPU 10
[90701.679808] Pid: 9627, comm: ls Tainted: G        W    3.7.1+ #10 QCI QSSC-S4R/QSSC-S4R
[90701.688950] RIP: 0010:[<ffffffff814a343e>]  [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.698383] RSP: 0018:ffff88177b431bb8  EFLAGS: 00010206
[90701.704309] RAX: ffff88177b431fd8 RBX: 00007ffffffff000 RCX: ffff88177b431bec
[90701.712271] RDX: 0000000000000003 RSI: 0000000000000006 RDI: 0000000000000000
[90701.720223] RBP: ffff88177b431bc8 R08: 0000000000000004 R09: 0000000000000000
[90701.728185] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
[90701.736147] R13: ffff88184ef92000 R14: 0000000000000023 R15: ffff88177b431c88
[90701.744109] FS:  00007fd56a1a47c0(0000) GS:ffff88105fc40000(0000) knlGS:0000000000000000
[90701.753137] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[90701.759550] CR2: 0000000000000028 CR3: 000000104f15f000 CR4: 00000000000007e0
[90701.767512] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[90701.775465] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[90701.783428] Process ls (pid: 9627, threadinfo ffff88177b430000, task ffff88185ca4cb60)
[90701.792261] Stack:
[90701.794505]  0000000000000023 ffff88177b431c50 ffff88177b431c38 ffffffffa014fcb1
[90701.802809]  ffff88184ef921bc 0000000000000000 00000001ffffffff ffff88184ef921c0
[90701.811123]  ffff88177b431c08 ffffffff815ca3d9 ffff88177b431c18 ffff880857758000
[90701.819433] Call Trace:
[90701.822183]  [<ffffffffa014fcb1>] smb_send_rqst+0x71/0x1f0 [cifs]
[90701.828991]  [<ffffffff815ca3d9>] ? schedule+0x29/0x70
[90701.834736]  [<ffffffffa014fe6d>] smb_sendv+0x3d/0x40 [cifs]
[90701.841062]  [<ffffffffa014fe96>] smb_send+0x26/0x30 [cifs]
[90701.847291]  [<ffffffffa015801f>] send_nt_cancel+0x6f/0xd0 [cifs]
[90701.854102]  [<ffffffffa015075e>] SendReceive+0x18e/0x360 [cifs]
[90701.860814]  [<ffffffffa0134a78>] CIFSFindFirst+0x1a8/0x3f0 [cifs]
[90701.867724]  [<ffffffffa013f731>] ? build_path_from_dentry+0xf1/0x260 [cifs]
[90701.875601]  [<ffffffffa013f731>] ? build_path_from_dentry+0xf1/0x260 [cifs]
[90701.883477]  [<ffffffffa01578e6>] cifs_query_dir_first+0x26/0x30 [cifs]
[90701.890869]  [<ffffffffa015480d>] initiate_cifs_search+0xed/0x250 [cifs]
[90701.898354]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.904486]  [<ffffffffa01554cb>] cifs_readdir+0x45b/0x8f0 [cifs]
[90701.911288]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.917410]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.923533]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.929657]  [<ffffffff81195848>] vfs_readdir+0xb8/0xe0
[90701.935490]  [<ffffffff81195b9f>] sys_getdents+0x8f/0x110
[90701.941521]  [<ffffffff815d3b99>] system_call_fastpath+0x16/0x1b
[90701.948222] Code: 66 90 55 65 48 8b 04 25 f0 c6 00 00 48 89 e5 53 48 83 ec 08 83 fe 01 48 8b 98 48 e0 ff ff 48 c7 80 48 e0 ff ff ff ff ff ff 74 22 <48> 8b 47 28 ff 50 68 65 48 8b 14 25 f0 c6 00 00 48 89 9a 48 e0
[90701.970313] RIP  [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.977125]  RSP <ffff88177b431bb8>
[90701.981018] CR2: 0000000000000028
[90701.984809] ---[ end trace 24bd602971110a43 ]---

This is likely due to a race vs. a reconnection event.

The current code checks for a NULL socket in smb_send_kvec, but that's
too late. By the time that check is done, the socket will already have
been passed to kernel_setsockopt. Move the check into smb_send_rqst, so
that it's checked earlier.

In truth, this is a bit of a half-assed fix. The -ENOTSOCK error
return here looks like it could bubble back up to userspace. The locking
rules around the ssocket pointer are really unclear as well. There are
cases where the ssocket pointer is changed without holding the srv_mutex,
but I'm not clear whether there's a potential race here yet or not.

This code seems like it could benefit from some fundamental re-think of
how the socket handling should behave. Until then though, this patch
should at least fix the above oops in most cases.

Cc: <stable@vger.kernel.org> # 3.7+
Reported-and-Tested-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-12-30 11:38:58 -06:00
..
9p The following changes since commit 4cbe5a555f: 2012-10-12 09:59:23 +09:00
adfs adfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
affs affs: drop vmtruncate 2012-12-20 14:00:01 -05:00
afs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
autofs4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
befs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
bfs bfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-12-20 18:14:31 -08:00
cachefiles FS-Cache: Mark cancellation of in-progress operation 2012-12-20 22:34:00 +00:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2012-12-20 14:00:13 -08:00
cifs cifs: move check for NULL socket into smb_send_rqst 2012-12-30 11:38:58 -06:00
coda fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
configfs lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
cramfs userns: Convert cramfs to use kuid/kgid where appropriate 2012-09-21 03:13:08 -07:00
debugfs fs/debugsfs: remove unnecessary inode->i_private initialization 2012-11-15 17:46:42 -08:00
devpts TTY: devpts, document devpts inode operations 2012-10-22 16:50:13 -07:00
dlm dlm: fix lvb invalidation conditions 2012-11-16 11:20:42 -06:00
ecryptfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
efs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
exofs exofs: don't leak io_state and pages on read error 2012-12-14 12:17:32 +02:00
exportfs Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux 2012-12-20 14:04:11 -08:00
ext2 ext2: fix return values on parse_options() failure 2012-10-09 23:23:53 +02:00
ext3 lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
ext4 lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
f2fs f2fs: Don't assign e_id in f2fs_acl_from_disk 2012-12-25 20:05:15 -08:00
fat fat: fix incorrect function comment 2012-12-20 17:40:20 -08:00
freevxfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
fscache FS-Cache: Clear remaining page count on retrieval cancellation 2012-12-20 22:35:15 +00:00
fuse Merge branch 'akpm' (Andrew's patch-bomb) 2012-12-17 20:58:12 -08:00
gfs2 lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
hfs hfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
hfsplus Merge branch 'akpm' (Andrew's patch-bomb) 2012-12-20 20:00:43 -08:00
hostfs Merge branch 'for-linus-37rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2012-10-10 11:15:20 +09:00
hpfs hpfs: drop vmtruncate 2012-12-20 18:40:00 -05:00
hppfs pidns: Use task_active_pid_ns where appropriate 2012-11-19 05:59:09 -08:00
hugetlbfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
isofs tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking 2012-10-09 23:33:55 -04:00
jbd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
jbd2 There are two major features for this merge window. The first is 2012-12-16 17:33:01 -08:00
jffs2 jffs2: hold erase_completion_lock on exit 2012-11-18 11:59:01 +02:00
jfs jfs: drop vmtruncate 2012-12-20 18:40:52 -05:00
lockd lockd: Remove BUG_ON()s from fs/lockd/clntproc.c 2012-11-04 14:43:40 -05:00
logfs logfs: drop vmtruncate 2012-12-20 18:40:53 -05:00
minix minix: drop vmtruncate 2012-12-20 18:40:53 -05:00
ncpfs ncpfs: drop vmtruncate 2012-12-20 18:40:54 -05:00
nfs NFS: Kill fscache warnings when mounting without -ofsc 2012-12-21 08:32:09 -08:00
nfs_common
nfsd Revert "nfsd: warn on odd reply state in nfsd_vfs_read" 2012-12-21 17:07:45 -08:00
nilfs2 nilfs2: drop vmtruncate 2012-12-20 18:40:54 -05:00
nls
notify Merge branch 'for-next' of git://git.infradead.org/users/eparis/notify 2012-12-20 20:11:52 -08:00
ntfs ntfs: drop vmtruncate 2012-12-20 18:40:55 -05:00
ocfs2 ocfs2: drop vmtruncate 2012-12-20 14:00:01 -05:00
omfs omfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
openpromfs fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
proc proc: Allow proc_free_inum to be called from any context 2012-12-25 16:23:12 -08:00
pstore lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
qnx4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
qnx6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
quota quota: Use the pre-processor to compile out quotactl_cmd_write when !CONFIG_BLOCK 2012-12-13 16:33:24 +01:00
ramfs
reiserfs reiserfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
romfs fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
squashfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
sysfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
sysv sysv: drop vmtruncate 2012-12-20 14:00:01 -05:00
ubifs ubifs: use prandom_bytes 2012-12-17 17:15:26 -08:00
udf udf: remove un-needed variable from inode_getblk 2012-12-13 16:33:23 +01:00
ufs ufs: drop vmtruncate 2012-12-20 14:00:01 -05:00
xfs xfs: fix sparse reported log CRC endian issue 2012-12-03 12:10:59 -06:00
aio.c
anon_inodes.c
attr.c userns: Allow chown and setgid preservation 2012-11-20 04:17:24 -08:00
bad_inode.c lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
binfmt_aout.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
binfmt_elf_fdpic.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
binfmt_elf.c binfmt_elf: fix corner case kfree of uninitialized data 2012-12-17 17:15:19 -08:00
binfmt_em86.c exec: use -ELOOP for max recursion depth 2012-12-17 17:15:23 -08:00
binfmt_flat.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
binfmt_misc.c exec: do not leave bprm->interp on stack 2012-12-20 17:40:19 -08:00
binfmt_script.c exec: do not leave bprm->interp on stack 2012-12-20 17:40:19 -08:00
binfmt_som.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
bio-integrity.c block: Ues bi_pool for bio_integrity_alloc() 2012-09-09 10:35:38 +02:00
bio.c vfs: fix: don't increase bio_slab_max if krealloc() fails 2012-10-22 22:00:26 +02:00
block_dev.c lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
buffer.c fs/buffer.c: remove redundant initialization in alloc_page_buffers() 2012-12-12 17:38:35 -08:00
char_dev.c char_dev: pin parent kobject 2012-10-22 08:50:37 +03:00
compat_binfmt_elf.c coredump: extend core dump note section to contain file names of mapped files 2012-10-06 03:05:17 +09:00
compat_ioctl.c Merge 3.7-rc3 into tty-next 2012-10-29 09:00:57 -07:00
compat.c vfs: define struct filename and have getname() return it 2012-10-12 20:14:55 -04:00
coredump.c do_coredump(): get rid of pt_regs argument 2012-11-29 00:01:25 -05:00
coredump.h coredump: update coredump-related headers 2012-10-06 03:05:15 +09:00
dcache.c vfs: d_obtain_alias() needs to use "/" as default name. 2012-12-20 18:49:10 -05:00
dcookies.c
direct-io.c direct-io: don't read inode->i_blkbits multiple times 2012-11-29 12:38:44 -08:00
drop_caches.c
eventfd.c fs, eventfd: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
eventpoll.c fs, epoll: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
exec.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-12-20 20:00:43 -08:00
fcntl.c Fix F_DUPFD_CLOEXEC breakage 2012-10-09 15:52:31 +09:00
fhandle.c Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux 2012-12-20 14:04:11 -08:00
fifo.c
file_table.c fs: Fix imbalance in freeze protection in mark_files_ro() 2012-12-20 13:57:36 -05:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-12-12 12:22:13 -08:00
filesystems.c vfs: define struct filename and have getname() return it 2012-10-12 20:14:55 -04:00
fs_struct.c kill daemonize() 2012-11-28 21:49:02 -05:00
fs-writeback.c writeback: fix a typo in comment 2012-12-12 17:38:34 -08:00
generic_acl.c userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr 2012-09-18 01:01:35 -07:00
inode.c mm: redefine address_space.assoc_mapping 2012-12-11 17:22:26 -08:00
internal.h writeback: put unused inodes to LRU after writeback completion 2012-11-26 17:41:24 -08:00
ioctl.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
ioprio.c
Kconfig Introduce a new file system, Flash-Friendly File System (F2FS), to Linux 3.8. 2012-12-20 13:54:52 -08:00
Kconfig.binfmt coredump: make core dump functionality optional 2012-10-06 03:05:15 +09:00
libfs.c vfs: drop vmtruncate 2012-12-20 18:46:29 -05:00
locks.c UAPI Disintegration 2012-10-09 2012-10-09 18:35:22 -04:00
Makefile f2fs: update Kconfig and Makefile 2012-12-11 13:43:42 +09:00
mbcache.c
mount.h proc: Usable inode numbers for the namespace file descriptors. 2012-11-20 04:19:49 -08:00
mpage.c
namei.c vfs: fix renameat to retry on ESTALE errors 2012-12-20 18:50:05 -05:00
namespace.c vfs, freeze: use ACCESS_ONCE() to guard access to ->mnt_flags 2012-12-20 13:36:18 -05:00
no-block.c
open.c vfs: make fchownat retry once on ESTALE errors 2012-12-20 18:50:07 -05:00
pipe.c pipe(2) - race-free error recovery 2012-09-26 21:08:52 -04:00
pnode.c
pnode.h vfs: Only support slave subtrees across different user namespaces 2012-11-19 05:59:20 -08:00
posix_acl.c userns: Convert vfs posix_acl support to use kuids and kgids 2012-09-18 01:01:35 -07:00
proc_namespace.c
read_write.c sendfile: allows bypassing of notifier events 2012-12-20 17:40:21 -08:00
read_write.h compat: fs: Generic compat_sys_sendfile implementation 2012-10-02 21:35:55 -04:00
readdir.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
select.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
seq_file.c lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
signalfd.c fs, epoll: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
splice.c writeback: remove nr_pages_dirtied arg from balance_dirty_pages_ratelimited_nr() 2012-12-11 17:22:21 -08:00
stack.c
stat.c vfs: fix readlinkat to retry on ESTALE 2012-12-20 18:50:01 -05:00
statfs.c vfs: fix user_statfs to retry once on ESTALE errors 2012-12-20 18:50:07 -05:00
super.c vfs: drop lock/unlock super 2012-10-09 23:33:39 -04:00
sync.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
timerfd.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
utimes.c vfs: allow utimensat() calls to retry once on an ESTALE error 2012-12-20 18:50:08 -05:00
xattr_acl.c userns: Fix posix_acl_file_xattr_userns gid conversion 2012-10-12 13:16:48 -07:00
xattr.c vfs: make lremovexattr retry once on ESTALE error 2012-12-20 18:50:11 -05:00