syzbot


possible deadlock in chown_common

Status: fixed on 2024/01/30 15:47
Subsystems: reiserfs
[Documentation on labels]
Reported-by: syzbot+3abaeed5039cc1c49c7c@syzkaller.appspotmail.com
Fix commit: 6f861765464f fs: Block writes to mounted block devices
First crash: 565d, last: 92d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: fixed by (bisect log) :
commit 6f861765464f43a71462d52026fbddfc858239a5
Author: Jan Kara <jack@suse.cz>
Date: Wed Nov 1 17:43:10 2023 +0000

  fs: Block writes to mounted block devices

  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] possible deadlock in chown_common 2 (4) 2024/01/18 14:40
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 possible deadlock in chown_common C 1 426d 566d 0/1 upstream: reported C repro on 2022/10/05 17:28
linux-5.15 possible deadlock in chown_common 5 23h02m 232d 0/3 upstream: reported on 2023/09/04 16:29
linux-6.1 possible deadlock in chown_common (2) 1 21d 21d 0/3 upstream: reported on 2024/04/02 11:14
linux-6.1 possible deadlock in chown_common 1 278d 278d 0/3 auto-obsoleted due to no activity on 2023/10/28 14:17
Last patch testing requests (3)
Created Duration User Patch Repo Result
2024/01/11 18:34 23m retest repro linux-next OK log
2023/11/02 16:11 14m retest repro linux-next report log
2023/08/21 16:27 23m retest repro linux-next report log
Fix bisection attempts (7)
Created Duration User Patch Repo Result
2024/01/17 11:14 5h04m bisect fix upstream job log (1)
2023/12/03 09:26 1h19m bisect fix upstream job log (0) log
2023/09/26 21:50 1h04m bisect fix upstream job log (0) log
2023/07/21 08:48 2h20m bisect fix upstream job log (0) log
2023/02/28 05:51 43m bisect fix upstream job log (0) log
2023/01/23 12:32 45m (2) bisect fix upstream job log (0) log
2022/11/05 04:42 36m bisect fix upstream job log (0) log

Sample crash report:
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using rupasov hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.0.0-syzkaller-03015-g2bca25eaeba6 #0 Not tainted
------------------------------------------------------
syz-executor428/3608 is trying to acquire lock:
ffff8880704302e0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
ffff8880704302e0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: chown_common+0x414/0x8f0 fs/open.c:729

but task is already holding lock:
ffff888020438460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (sb_writers#9){.+.+}-{0:0}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
       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

-> #1 (&sbi->lock){+.+.}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
       __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:2176
       mount_bdev+0x26c/0x3a0 fs/super.c:1400
       legacy_get_tree+0xea/0x180 fs/fs_context.c:610
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       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

-> #0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain+0x18c1/0x6bd0 kernel/locking/lockdep.c:3829
       __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
       down_write+0x95/0x170 kernel/locking/rwsem.c:1552
       inode_lock include/linux/fs.h:756 [inline]
       chown_common+0x414/0x8f0 fs/open.c:729
       do_fchownat+0x165/0x240 fs/open.c:767
       __do_sys_lchown fs/open.c:792 [inline]
       __se_sys_lchown fs/open.c:790 [inline]
       __x64_sys_lchown+0x81/0x90 fs/open.c:790
       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:
  &type->i_mutex_dir_key#6 --> &sbi->lock --> sb_writers#9

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

1 lock held by syz-executor428/3608:
 #0: ffff888020438460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393

stack backtrace:
CPU: 0 PID: 3608 Comm: syz-executor428 Not tainted 6.0.0-syzkaller-03015-g2bca25eaeba6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
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:2175
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain+0x18c1/0x6bd0 kernel/locking/lockdep.c:3829
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
 down_write+0x95/0x170 kernel/locking/rwsem.c:1552
 inode_lock include/linux/fs.h:756 [inline]
 chown_common+0x414/0x8f0 fs/open.c:729
 do_fchownat+0x165/0x240 fs/open.c:767
 __do_sys_lchown fs/open.c:792 [inline]
 __se_sys_lchown fs/open.c:790 [inline]
 __x64_sys_lchown+0x81/0x90 fs/open.c:790
 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: 0033:0x7f7b93991899
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007ffcd35199f8 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b93991899
RDX: 0000000000000000 RSI: 000000000000ee01 RDI: 0000000020000080
RBP: 0000000000000000 R08: 00007f7b939ffec0 R09: 00007f7b939ffec0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcd3519a20
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000
 </TASK>

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/10/06 03:06 upstream 2bca25eaeba6 2c6543ad .config strace log report syz C [disk image] [vmlinux] [mounted in repro] ci2-upstream-fs possible deadlock in chown_common
2022/11/07 02:47 linux-next 0cdb3579f1ee 6d752409 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root possible deadlock in chown_common
2023/04/23 22:04 upstream 457391b03803 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/04/20 07:55 upstream 789b4a41c247 a219f34e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/04/20 05:31 upstream 789b4a41c247 a219f34e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/04/13 10:43 upstream de4664485abb 82d5e53e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/04/08 14:50 upstream aa318c48808c 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/04/07 06:49 upstream f2afccfefe7b 00ce4c67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/03/24 15:03 upstream 1e760fa3596e 9700afae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2023/03/23 20:47 upstream 9fd6ba5420ba f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in chown_common
2024/01/22 14:28 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 0802e17d9aca 9bd8dcda .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/12/17 14:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d5b235ec8eab 3222d10c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/10/19 15:28 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 78124b0c1d10 42e1d524 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/06/09 01:36 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 908f31f2a05b 7086cdb9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/05/27 16:57 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci eb0f1697d729 cf184559 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/05/05 03:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 518a39a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/05/01 15:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/04/27 13:37 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 6f5b1cc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/04/27 11:19 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 6f5b1cc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/04/24 15:01 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a fdc18293 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/04/23 09:37 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
2023/04/21 14:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 14f8db1c0f9a 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in chown_common
* Struck through repros no longer work on HEAD.