syzbot


possible deadlock in deactivate_super (2)

Status: upstream: reported C repro on 2025/02/02 14:09
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+180dd013ba371eabc162@syzkaller.appspotmail.com
First crash: 6d16h, last: 51m
Cause bisection: the cause commit could be any of (bisect log):
  309a43165077 rcu/kvfree: Use consistent krcp when growing kfree_rcu() page cache
  021a5ff84743 rcu/kvfree: Do not run a page work if a cache is disabled
  1e237994d9c9 rcu/kvfree: Invoke debug_rcu_bhead_unqueue() after checking bnode->gp_snap
  60888b77a06e rcu/kvfree: Make fill page cache start from krcp->nr_bkv_objs
  f32276a37652 rcu/kvfree: Add debug check for GP complete for kfree_rcu_cpu list
  6b706e5603c4 rcu/kvfree: Make drain_page_cache() take early return if cache is disabled
  cdfa0f6fa6b7 rcu/kvfree: Add debug to check grace periods
  2e31da752c6d Merge branches 'doc.2023.05.10a', 'fixes.2023.05.11a', 'kvfree.2023.05.10a', 'nocb.2023.05.11a', 'rcu-tasks.2023.05.10a', 'torture.2023.05.15a' and 'rcu-urgent.2023.06.06a' into HEAD
  7e3f926bf453 rcu/kvfree: Eliminate k[v]free_rcu() single argument macro
  af96134dc856 Merge tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] possible deadlock in deactivate_super (2) 0 (1) 2025/02/02 14:09
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in deactivate_super C 136 9h55m 6d12h 0/3 upstream: reported C repro on 2025/01/29 18:51
upstream possible deadlock in deactivate_super ext4 C unreliable 9 1022d 1042d 0/28 closed as dup on 2022/03/30 22:17
linux-6.1 possible deadlock in deactivate_super C 131 9h44m 6d10h 0/3 upstream: reported C repro on 2025/01/29 20:18

Sample crash report:
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Not tainted
------------------------------------------------------
syz-executor386/5821 is trying to acquire lock:
ffff8880274d4148 ((wq_completion)ocfs2_wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0xb1/0x170 kernel/workqueue.c:3905

but task is already holding lock:
ffff88807c79a0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
ffff88807c79a0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
ffff88807c79a0e0 (&type->s_umount_key#45){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&type->s_umount_key#45){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_finish_quota_recovery+0x15c/0x22a0 fs/ocfs2/quota_local.c:603
       ocfs2_complete_recovery+0x17c1/0x25c0 fs/ocfs2/journal.c:1357
       process_one_work kernel/workqueue.c:3236 [inline]
       process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
       worker_thread+0x870/0xd30 kernel/workqueue.c:3398
       kthread+0x7a9/0x920 kernel/kthread.c:464
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #1 ((work_completion)(&journal->j_recovery_work)){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       process_one_work kernel/workqueue.c:3212 [inline]
       process_scheduled_works+0x994/0x1840 kernel/workqueue.c:3317
       worker_thread+0x870/0xd30 kernel/workqueue.c:3398
       kthread+0x7a9/0x920 kernel/kthread.c:464
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 ((wq_completion)ocfs2_wq){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       touch_wq_lockdep_map+0xc7/0x170 kernel/workqueue.c:3905
       __flush_workqueue+0x14a/0x1280 kernel/workqueue.c:3947
       ocfs2_shutdown_local_alloc+0x109/0xa90 fs/ocfs2/localalloc.c:380
       ocfs2_dismount_volume+0x202/0x910 fs/ocfs2/super.c:1822
       generic_shutdown_super+0x139/0x2d0 fs/super.c:642
       kill_block_super+0x44/0x90 fs/super.c:1710
       deactivate_locked_super+0xc4/0x130 fs/super.c:473
       cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1413
       task_work_run+0x24f/0x310 kernel/task_work.c:227
       exit_task_work include/linux/task_work.h:40 [inline]
       do_exit+0xa2a/0x28e0 kernel/exit.c:938
       do_group_exit+0x207/0x2c0 kernel/exit.c:1087
       __do_sys_exit_group kernel/exit.c:1098 [inline]
       __se_sys_exit_group kernel/exit.c:1096 [inline]
       __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
       x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  (wq_completion)ocfs2_wq --> (work_completion)(&journal->j_recovery_work) --> &type->s_umount_key#45

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&type->s_umount_key#45);
                               lock((work_completion)(&journal->j_recovery_work));
                               lock(&type->s_umount_key#45);
  lock((wq_completion)ocfs2_wq);

 *** DEADLOCK ***

1 lock held by syz-executor386/5821:
 #0: ffff88807c79a0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807c79a0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807c79a0e0 (&type->s_umount_key#45){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505

stack backtrace:
CPU: 0 UID: 0 PID: 5821 Comm: syz-executor386 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 touch_wq_lockdep_map+0xc7/0x170 kernel/workqueue.c:3905
 __flush_workqueue+0x14a/0x1280 kernel/workqueue.c:3947
 ocfs2_shutdown_local_alloc+0x109/0xa90 fs/ocfs2/localalloc.c:380
 ocfs2_dismount_volume+0x202/0x910 fs/ocfs2/super.c:1822
 generic_shutdown_super+0x139/0x2d0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1710
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1413
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4d4cea0b89
Code: Unable to access opcode bytes at 0x7f4d4cea0b5f.
RSP: 002b:00007ffd2ffac3e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d4cea0b89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007f4d4cf212b0 R08: ffffffffffffffb8 R09: 0000000000004701
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d4cf212b0
R13: 0000000000000000 R14: 00007f4d4cf22020 R15: 00007

Crashes (404):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/04 07:00 upstream 0de63bb7d919 8f267cef .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 04:21 upstream 69b8923f5003 568559e4 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/01 22:31 upstream 69b8923f5003 568559e4 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/01 16:35 upstream 69b8923f5003 aa47157c .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/01 14:09 upstream 69b8923f5003 aa47157c .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/01 13:55 upstream 69b8923f5003 aa47157c .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/01 13:22 upstream 69b8923f5003 aa47157c .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/01 05:35 upstream 69b8923f5003 aa47157c .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 06:38 upstream 0de63bb7d919 8f267cef .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root possible deadlock in deactivate_super
2025/02/03 03:18 upstream 69e858e0b8b2 568559e4 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root possible deadlock in deactivate_super
2025/01/29 14:00 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 1950a0af2d55 865ef71e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 possible deadlock in deactivate_super
2025/02/05 06:08 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/05 05:07 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/05 04:37 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/05 03:33 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/05 02:06 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/05 00:59 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 23:26 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 20:57 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 19:23 upstream d009de7d5428 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 17:44 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 16:28 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 14:39 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 13:44 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 12:24 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 10:57 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 09:53 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 08:27 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 06:03 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 05:47 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 04:19 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 02:02 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/04 00:38 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 23:15 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 22:08 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 21:46 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 20:39 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 18:09 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 16:35 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 14:16 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 11:25 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 11:22 upstream 2014c95afece a21a8419 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 10:05 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 08:56 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 08:17 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 07:02 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 05:38 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 01:54 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 01:41 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/03 00:32 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/02 23:11 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/02 20:31 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/02 18:29 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
2025/02/02 17:17 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in deactivate_super
* Struck through repros no longer work on HEAD.