[syzbot] [ocfs2?] possible deadlock in deactivate_super (2)

From: syzbot
Date: Sun Feb 02 2025 - 09:09:25 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 69b8923f5003 Merge tag 'for-linus-6.14-ofs4' of git://git...
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13fc4eb0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=57ab43c279fa614d
dashboard link: https://syzkaller.appspot.com/bug?extid=180dd013ba371eabc162
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17cdcb24580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132c2d18580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ea84ac864e92/disk-69b8923f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6a465997b4e0/vmlinux-69b8923f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d72b67b2bd15/bzImage-69b8923f.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/48dd26198522/mount_0.gz

Bisection is inconclusive: the first bad commit could be any of:

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

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11821724580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+180dd013ba371eabc162@xxxxxxxxxxxxxxxxxxxxxxxxx

ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.13.0-syzkaller-09793-g69b8923f5003 #0 Not tainted
------------------------------------------------------
syz-executor651/5821 is trying to acquire lock:
ffff8880270c2948 ((wq_completion)ocfs2_wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0xb1/0x170 kernel/workqueue.c:3905

but task is already holding lock:
ffff88807ea340e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
ffff88807ea340e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
ffff88807ea340e0 (&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-executor651/5821:
#0: ffff88807ea340e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88807ea340e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88807ea340e0 (&type->s_umount_key#45){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505

stack backtrace:
CPU: 1 UID: 0 PID: 5821 Comm: syz-executor651 Not tainted 6.13.0-syzkaller-09793-g69b8923f5003 #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: 0033:0x7fefe6fc9b89
Code: Unable to access opcode bytes at 0x7fefe6fc9b5f.
RSP: 002b:00007ffcff91e9b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fefe6fc9b89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007fefe704a2b0 R08: ffffffffffffffb8 R09: 0000000000004701
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fefe704a2b0
R13: 0000000000000000 R14: 00007fefe704b020 R15: 00007fefe6f980

---
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Next message: Krzysztof Kozlowski: "Re: [PATCH v1 1/2] dt-bindings: usb: snps,dwc3: Add property for imod"
Previous message: Ferass El Hafidi: "Re: [PATCH v2 1/2] dt-bindings: arm: amlogic: add S805Y and Mi TV Stick"
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