syzbot


possible deadlock in mnt_want_write_file

Status: upstream: reported C repro on 2022/11/03 22:02
Reported-by: syzbot+1047e42179f502f2b0a2@syzkaller.appspotmail.com
First crash: 25d, last: 12h48m

Cause bisection: failed (bisect log)
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 possible deadlock in mnt_want_write_file C 1 22d 52d 0/1 upstream: reported C repro on 2022/10/07 22:29
linux-4.19 possible deadlock in mnt_want_write_file C 9 22h09m 36d 0/1 upstream: reported C repro on 2022/10/23 23:32
Patch testing requests:
Created Duration User Patch Repo Result
2022/11/23 23:12 26m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git eb7081409f94 OK log
2022/11/23 12:02 13m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git eb7081409f94 error
2022/11/23 08:48 27m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git eb7081409f94 report log

Sample crash report:
REISERFS (device loop0): Using r5 hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc6-syzkaller-00176-g08ad43d554ba #0 Not tainted
------------------------------------------------------
syz-executor333/3631 is trying to acquire lock:
ffff888026314460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437

but task is already holding lock:
ffff88801f5e2090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sbi->lock){+.+.}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       __mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
       reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27
       reiserfs_lookup+0x147/0x490 fs/reiserfs/namei.c:364
       __lookup_slow+0x266/0x3a0 fs/namei.c:1685
       lookup_one_len+0x430/0x690 fs/namei.c:2711
       reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:973
       reiserfs_fill_super+0x2071/0x24a0 fs/reiserfs/super.c:2174
       mount_bdev+0x26c/0x3a0 fs/super.c:1401
       legacy_get_tree+0xea/0x180 fs/fs_context.c:610
       vfs_get_tree+0x88/0x270 fs/super.c:1531
       do_new_mount+0x289/0xad0 fs/namespace.c:3040
       do_mount fs/namespace.c:3383 [inline]
       __do_sys_mount fs/namespace.c:3591 [inline]
       __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&type->i_mutex_dir_key#6){+.+.}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       down_write+0x9c/0x270 kernel/locking/rwsem.c:1562
       inode_lock include/linux/fs.h:756 [inline]
       open_last_lookups fs/namei.c:3478 [inline]
       path_openat+0x7b9/0x2df0 fs/namei.c:3710
       do_filp_open+0x264/0x4f0 fs/namei.c:3740
       do_sys_openat2+0x124/0x4e0 fs/open.c:1310
       do_sys_open fs/open.c:1326 [inline]
       __do_sys_openat fs/open.c:1342 [inline]
       __se_sys_openat fs/open.c:1337 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1337
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (sb_writers#9){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
       __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1826 [inline]
       sb_start_write+0x4d/0x1a0 include/linux/fs.h:1901
       mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437
       reiserfs_ioctl+0x16e/0x340 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  sb_writers#9 --> &type->i_mutex_dir_key#6 --> &sbi->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(&type->i_mutex_dir_key#6);
                               lock(&sbi->lock);
  lock(sb_writers#9);

 *** DEADLOCK ***

1 lock held by syz-executor333/3631:
 #0: ffff88801f5e2090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 0 PID: 3631 Comm: syz-executor333 Not tainted 6.1.0-rc6-syzkaller-00176-g08ad43d554ba #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1826 [inline]
 sb_start_write+0x4d/0x1a0 include/linux/fs.h:1901
 mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437
 reiserfs_ioctl+0x16e/0x340 fs/reiserfs/ioctl.c:103
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fe707070ad9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc4b3bbe28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010

Crashes (63):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-fs 2022/11/25 23:03 upstream 08ad43d554ba f4470a7b .config log report syz C possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/23 02:32 upstream eb7081409f94 9da37ae8 .config log report syz C possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/28 23:06 upstream b7b275e60bcd 247de55b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/28 19:40 upstream b7b275e60bcd 247de55b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/28 17:16 upstream b7b275e60bcd 247de55b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/27 16:00 upstream faf68e3523c2 f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/27 12:18 upstream faf68e3523c2 f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/26 17:04 upstream 644e9524388a f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/26 15:59 upstream 644e9524388a f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/26 10:07 upstream 08ad43d554ba f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/26 08:48 upstream 08ad43d554ba f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/26 05:03 upstream 08ad43d554ba f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/25 22:11 upstream 08ad43d554ba f4470a7b .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/25 00:53 upstream 4312098baf37 ff68ff8f .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/24 11:35 upstream 4312098baf37 ff68ff8f .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/24 04:35 upstream eb7081409f94 52fdf57a .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/23 21:19 upstream eb7081409f94 52fdf57a .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/23 07:19 upstream eb7081409f94 9da37ae8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/23 02:21 upstream eb7081409f94 9da37ae8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/22 01:59 upstream eb7081409f94 1c576c23 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/21 22:49 upstream eb7081409f94 1c576c23 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/20 15:29 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/20 15:04 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/20 07:28 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/19 16:31 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/19 13:40 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/19 12:40 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/18 09:32 upstream 84368d882b96 5bb70014 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/17 21:08 upstream 81ac25651a62 4ba8ab94 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/17 06:06 upstream 59d0d52c30d4 3a127a31 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/17 02:23 upstream 59d0d52c30d4 3a127a31 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/16 15:45 upstream 81e7cfa3a9eb 3a127a31 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/16 02:45 upstream 81e7cfa3a9eb 3a127a31 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/15 22:45 upstream 81e7cfa3a9eb 3a127a31 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/14 10:27 upstream 094226ad94f4 943f4cb8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/14 09:14 upstream 094226ad94f4 7ba4d859 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/14 06:37 upstream af7a05689189 7ba4d859 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/13 21:22 upstream af7a05689189 7ba4d859 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/13 17:16 upstream af7a05689189 7ba4d859 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/12 23:22 upstream 8f2975c2bb4c f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/12 09:45 upstream 8f2975c2bb4c f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/11 19:24 upstream eb037f16f7e8 f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/11 17:52 upstream 4bbf3422df78 f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/11 12:14 upstream 4bbf3422df78 f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/11 11:40 upstream 4bbf3422df78 f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/11 07:24 upstream 4bbf3422df78 f42ee5d8 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/10 10:00 upstream f67dd6ce0723 b2488a87 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/10 07:47 upstream f67dd6ce0723 b2488a87 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/08 12:47 upstream 59f2f4b8a757 060f945e .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/07 12:02 upstream f0c4d9fc9cc9 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/06 22:42 upstream 089d1c31224e 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/06 06:15 upstream b208b9fbbcba 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/06 04:28 upstream b208b9fbbcba 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/06 01:36 upstream b208b9fbbcba 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/05 07:49 upstream 64c3dd0b98f5 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/05 06:33 upstream 64c3dd0b98f5 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/04 22:48 upstream ee6050c8af96 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/04 22:15 upstream ee6050c8af96 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/04 18:57 upstream ee6050c8af96 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/04 11:43 upstream ee6050c8af96 6d752409 .config log report info possible deadlock in mnt_want_write_file
ci2-upstream-fs 2022/11/03 19:57 upstream f2f32f8af2b0 7a2ebf95 .config log report info possible deadlock in mnt_want_write_file
* Struck through repros no longer work on HEAD.