github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-10 07:32:29 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph
ce7ec3d752
linux/fs
History
Rabin Vincent 11aa5c1010 block: protect iterate_bdevs() against concurrent close 
commit af309226db upstream.

If a block device is closed while iterate_bdevs() is handling it, the
following NULL pointer dereference occurs because bdev->b_disk is NULL
in bdev_get_queue(), which is called from blk_get_backing_dev_info() (in
turn called by the mapping_cap_writeback_dirty() call in
__filemap_fdatawrite_range()):

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000508
 IP: [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20
 PGD 9e62067 PUD 9ee8067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 1 PID: 2422 Comm: sync Not tainted 4.5.0-rc7+ #400
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
 task: ffff880009f4d700 ti: ffff880009f5c000 task.ti: ffff880009f5c000
 RIP: 0010:[<ffffffff81314790>]  [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20
 RSP: 0018:ffff880009f5fe68  EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff88000ec17a38 RCX: ffffffff81a4e940
 RDX: 7fffffffffffffff RSI: 0000000000000000 RDI: ffff88000ec176c0
 RBP: ffff880009f5fe68 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88000ec17860
 R13: ffffffff811b25c0 R14: ffff88000ec178e0 R15: ffff88000ec17a38
 FS:  00007faee505d700(0000) GS:ffff88000fb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000508 CR3: 0000000009e8a000 CR4: 00000000000006e0
 Stack:
  ffff880009f5feb8 ffffffff8112e7f5 0000000000000000 7fffffffffffffff
  0000000000000000 0000000000000000 7fffffffffffffff 0000000000000001
  ffff88000ec178e0 ffff88000ec17860 ffff880009f5fec8 ffffffff8112e81f
 Call Trace:
  [<ffffffff8112e7f5>] __filemap_fdatawrite_range+0x85/0x90
  [<ffffffff8112e81f>] filemap_fdatawrite+0x1f/0x30
  [<ffffffff811b25d6>] fdatawrite_one_bdev+0x16/0x20
  [<ffffffff811bc402>] iterate_bdevs+0xf2/0x130
  [<ffffffff811b2763>] sys_sync+0x63/0x90
  [<ffffffff815d4272>] entry_SYSCALL_64_fastpath+0x12/0x76
 Code: 0f 1f 44 00 00 48 8b 87 f0 00 00 00 55 48 89 e5 <48> 8b 80 08 05 00 00 5d
 RIP  [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20
  RSP <ffff880009f5fe68>
 CR2: 0000000000000508
 ---[ end trace 2487336ceb3de62d ]---

The crash is easily reproducible by running the following command, if an
msleep(100) is inserted before the call to func() in iterate_devs():

 while :; do head -c1 /dev/nullb0; done > /dev/null & while :; do sync; done

Fix it by holding the bd_mutex across the func() call and only calling
func() if the bdev is opened.

Fixes: 5c0d6b60a0 ("vfs: Create function for iterating over block devices")
Reported-and-tested-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-09 08:32:21 +01:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
adfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
affs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
afs afs: call->operation_ID sometimes used as __be32 sometimes as u32 2016-10-13 17:03:52 +01:00
autofs4 autofs: refactor ioctl fn vector in iookup_dev_ioctl() 2016-10-11 15:06:31 -07:00
befs befs fixes for 4.9-rc1 2016-10-15 12:09:13 -07:00
bfs Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
btrfs Btrfs: fix qgroup rescan worker initialization 2017-01-06 10:40:10 +01:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ceph ceph: don't set req->r_locked_dir in ceph_d_revalidate 2016-12-08 14:32:16 +01:00
cifs CIFS: Fix a possible memory corruption in push locks 2017-01-06 10:40:16 +01:00
coda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
configfs Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
cramfs more trivial ->iterate_shared conversions 2016-05-09 11:41:14 -04:00
crypto fscrypto: don't use on-stack buffer for key derivation 2016-11-19 20:56:13 -05:00
debugfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
devpts Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
dlm dlm: free workqueues after the connections 2016-10-10 09:54:00 -05:00
ecryptfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
efivarfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
efs fs/efs/super.c: fix return value 2016-05-20 17:58:30 -07:00
exofs fs: exofs: print a hex number after a 0x prefix 2016-10-27 18:43:43 -07:00
exportfs exportfs: be careful to only return expected errors. 2016-10-06 09:07:44 -04:00
ext2 ext2: avoid bogus -Wmaybe-uninitialized warning 2016-10-18 11:29:35 +02:00
ext4 ext4: do not perform data journaling when data is encrypted 2017-01-06 10:40:14 +01:00
f2fs f2fs: fix to determine start_cp_addr by sbi->cur_cp_pack 2017-01-06 10:40:14 +01:00
fat Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
freevxfs freevxfs: update Kconfig information 2016-06-13 10:20:39 +02:00
fscache Merge branch 'd_real' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc 2016-06-30 23:34:49 -04:00
fuse fuse: fix clearing suid, sgid for chown() 2016-12-06 16:18:45 +01:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hostfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hugetlbfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
isofs isofs: add KERN_CONT to printing of ER records 2016-11-30 10:41:26 -08:00
jbd2 jbd2: fix incorrect unlock on j_list_lock 2016-10-12 23:19:18 -04:00
jffs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
kernfs kernfs: Add noop_fsync to supported kernfs_file_fops 2016-10-27 17:47:11 +02:00
lockd treewide: remove redundant #include <linux/kconfig.h> 2016-10-11 15:06:33 -07:00
logfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
minix Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ncpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
nfs NFS client bugfixes for Linux 4.9 part 4 2016-11-23 14:43:40 -08:00
nfs_common
nfsd nfsd: Fix general protection fault in release_lock_stateid() 2016-11-01 15:24:43 -04:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
nls
notify fsnotify: clean up spinlock assertions 2016-10-07 18:46:26 -07:00
ntfs fs: remove the never implemented aio_fsync file operation 2016-10-30 13:09:42 -04:00
ocfs2 ocfs2: fix not enough credit panic 2016-11-11 08:12:37 -08:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
openpromfs fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
orangefs orangefs: add .owner to debugfs file_operations 2016-11-16 11:52:19 -05:00
overlayfs ovl: fix d_real() for stacked fs 2016-11-29 10:20:24 +01:00
proc proc: fix NULL dereference when reading /proc/<pid>/auxv 2016-10-27 18:43:43 -07:00
pstore Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
qnx4 more trivial ->iterate_shared conversions 2016-05-09 11:41:14 -04:00
qnx6 more trivial ->iterate_shared conversions 2016-05-09 11:41:14 -04:00
quota quota: fill in Q_XGETQSTAT inode information for inactive quotas 2016-08-15 17:43:31 +02:00
ramfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
reiserfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
romfs romfs, squashfs: switch to ->iterate_shared() 2016-05-09 11:41:15 -04:00
squashfs vfs: Remove {get,set,remove}xattr inode operations 2016-10-07 21:48:36 -04:00
sysfs Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2016-10-14 12:18:50 -07:00
sysv Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
tracefs fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
ubifs ubifs: Fix regression in ubifs_readdir() 2016-10-28 14:48:31 +02:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ufs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
xfs xfs: set AGI buffer type in xlog_recover_clear_agi_bucket 2017-01-06 10:40:17 +01:00
aio.c aio: fix freeze protection of aio writes 2016-10-30 13:09:42 -04:00
anon_inodes.c
attr.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
bad_inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
binfmt_aout.c fs: fix binfmt_aout.c build error 2016-05-28 16:34:59 -07:00
binfmt_elf_fdpic.c elf_fdpic_transfer_args_to_stack(): make it generic 2016-07-25 16:51:49 +10:00
binfmt_elf.c x86/coredump: Use pr_reg size, rather that TIF_IA32 flag 2016-09-14 21:28:10 +02:00
binfmt_em86.c fs/binfmt_em86.c: fix incompatible pointer type 2016-08-02 19:35:15 -04:00
binfmt_flat.c binfmt_flat: allow compressed flat binary format to work on MMU systems 2016-07-28 13:29:12 +10:00
binfmt_misc.c fs: Replace current_fs_time() with current_time() 2016-09-27 21:06:22 -04:00
binfmt_script.c
block_dev.c block: protect iterate_bdevs() against concurrent close 2017-01-09 08:32:21 +01:00
buffer.c fs: use mapping_set_error instead of opencoded set_bit 2016-10-11 15:06:33 -07:00
char_dev.c dax: define a unified inode/address_space for device-dax mappings 2016-08-23 22:58:51 -07:00
compat_binfmt_elf.c
compat_ioctl.c fs: compat_ioctl: add pretimeout functions for watchdogs 2016-09-24 09:27:18 +02:00
compat.c compat: remove compat_printk() 2016-09-27 21:20:53 -04:00
coredump.c coredump: fix unfreezable coredumping task 2016-11-11 08:12:37 -08:00
dax.c thp: reduce usage of huge zero page's atomic counter 2016-10-07 18:46:28 -07:00
dcache.c Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-08-07 10:01:14 -04:00
dcookies.c
direct-io.c consistent treatment of EFAULT on O_DIRECT read/write 2016-10-03 20:38:55 -04:00
drop_caches.c
eventfd.c eventfd: document lockless access in eventfd_poll 2016-03-22 15:36:02 -07:00
eventpoll.c fs: poll/select/recvmmsg: use timespec64 for timeout events 2016-05-19 19:12:14 -07:00
exec.c ptrace: Capture the ptracer's creds not PT_PTRACE_CAP 2017-01-06 10:40:13 +01:00
fcntl.c
fhandle.c fs/coredump: prevent fsuid=0 dumps into user-controlled directories 2016-03-22 15:36:02 -07:00
file_table.c
file.c fs/file: more unsigned file descriptors 2016-09-27 18:47:38 -04:00
filesystems.c
fs_pin.c
fs_struct.c
fs-writeback.c mm, writeback: flush plugged IO in wakeup_flusher_threads() 2016-08-09 19:58:06 -06:00
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 13:04:49 -07:00
ioctl.c vfs: cap dedupe request structure size at PAGE_SIZE 2016-09-15 13:29:52 -07:00
iomap.c fs: Do to trim high file position bits in iomap_page_mkwrite_actor 2016-10-24 14:20:25 +11:00
Kconfig mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGE 2016-10-07 18:46:29 -07:00
Kconfig.binfmt ARM: 8594/1: enable binfmt_flat on systems with an MMU 2016-08-12 16:47:05 +01:00
libfs.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
locks.c locking, fs/locks: Add missing file_sem locks 2016-10-18 12:21:28 +02:00
Makefile fs: introduce iomap infrastructure 2016-06-21 09:23:11 +10:00
mbcache.c mbcache: fix to detect failure of register_shrinker 2016-08-31 11:44:36 -04:00
mount.h mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
mpage.c block/mm: make bdev_ops->rw_page() take a bool for read/write 2016-08-07 14:41:02 -06:00
namei.c Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2016-10-14 17:23:33 -07:00
namespace.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
no-block.c
nsfs.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
open.c xfs: reflink update for 4.9-rc1 2016-10-13 20:28:22 -07:00
pipe.c pipe: cap initial pipe capacity according to pipe-max-size limit 2016-10-11 15:06:32 -07:00
pnode.c mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
pnode.h mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
posix_acl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
proc_namespace.c vfs: show_vfsstat: do not ignore errors from show_devname method 2016-03-16 13:09:08 -04:00
read_write.c iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector() 2016-10-14 20:00:34 -04:00
readdir.c restore killability of old mutex_lock_killable(&inode->i_mutex) users 2016-05-26 00:13:25 -04:00
select.c fs/select: add vmalloc fallback for select(2) 2016-10-11 15:06:30 -07:00
seq_file.c seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char 2016-10-07 18:46:30 -07:00
signalfd.c
splice.c splice: reinstate SIGPIPE/EPIPE handling 2017-01-06 10:40:12 +01:00
stack.c
stat.c
statfs.c
super.c fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths 2016-10-14 20:41:59 -04:00
sync.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
timerfd.c timerfd: Reject ALARM timerfds without CAP_WAKE_ALARM 2016-06-09 23:42:38 +02:00
userfaultfd.c mm: introduce fault_env 2016-07-26 16:19:19 -07:00
utimes.c Merge remote-tracking branch 'jk/vfs' into work.misc 2016-10-08 11:06:08 -04:00
xattr.c xattr: Fix setting security xattrs on sockfs 2016-11-17 00:00:23 -05:00