[v6.1] INFO: task hung in hfs_mdb_commit (5)
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syzbot
Apr 11, 2026, 7:52:35 AM (3 days ago) Apr 11
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 1989cd3d56e2 Linux 6.1.167
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13537f4e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=b9166ddb6029e3dd5c92
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1474e580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a8c0ce580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/814271465bd5/disk-1989cd3d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bd559379c491/vmlinux-1989cd3d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/063c12bf8ba7/bzImage-1989cd3d.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/9e75ea7a2b23/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b9166d...@syzkaller.appspotmail.com
INFO: task kworker/0:0:7 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0 state:D stack:24112 pid:7 ppid:2 flags:0x00004000
Workqueue: events_long flush_mdb
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit_lock+0xd8/0x580 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
lock_buffer include/linux/buffer_head.h:397 [inline]
hfs_mdb_commit+0x111/0x1100 fs/hfs/mdb.c:271
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
INFO: task syz-executor:4386 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21200 pid:4386 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit_lock+0xd8/0x580 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
lock_buffer include/linux/buffer_head.h:397 [inline]
hfs_mdb_commit+0xad2/0x1100 fs/hfs/mdb.c:325
hfs_sync_fs+0x11/0x20 fs/hfs/super.c:35
sync_filesystem+0xe6/0x220 fs/sync.c:56
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fed6ed9da57
RSP: 002b:00007ffc9afd7568 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fed6ee32048 RCX: 00007fed6ed9da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc9afd7620
RBP: 00007ffc9afd7620 R08: 00007ffc9afd8620 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc9afd86b0
R13: 00007fed6ee32048 R14: 0000000000024fcf R15: 00007ffc9afd86f0
</TASK>
Showing all locks held in the system:
2 locks held by kworker/0:0/7:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900000c7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2df30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e750 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
2 locks held by kworker/1:0/22:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/1:1/26:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90000a1fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by khungtaskd/28:
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/1:2/128:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002dc7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/1:3/3653:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900032b7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4029:
#0: ffff88814d3d6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by kworker/1:4/4329:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900043a7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/0:3/4333:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90004387d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/0:6/4369:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900032c7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by syz-executor/4386:
#0: ffff88807b9e40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4436:
#0: ffff888026fe40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4452:
#0: ffff88805d4b40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4467:
#0: ffff88802a4540e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4483:
#0: ffff88802a44a0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4509:
#0: ffff88805708c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4530:
#0: ffff888078b2e0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4552:
#0: ffff888075dc80e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4573:
#0: ffff888058f0c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
2 locks held by kworker/1:8/4582:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900038f7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 46 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0x5c/0xe0 kernel/kcov.c:349
Code: 41 54 53 48 8b 0c cd 38 25 90 8a 48 8b 54 24 20 65 4c 8b 05 06 f6 7f 7e 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 <65> 44 8b 1d f4 f5 7f 7e 41 81 e3 00 01 ff 00 74 13 41 81 fb 00 01
RSP: 0018:ffffc90000b772d8 EFLAGS: 00000206
RAX: 0000000000000028 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffffffff89b31534 RSI: ffffffff8dfafde0 RDI: 0000000000000001
RBP: ffffc90000b77690 R08: ffff88801dae5940 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000000 R12: ffff88807d7f209c
R13: 0000000000000001 R14: ffff88807d7f207c R15: 000000000000000a
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a904d63168 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
_ieee802_11_parse_elems_full+0x6a4/0x3640 net/mac80211/util.c:1051
ieee802_11_parse_elems_full+0xcdc/0x1220 net/mac80211/util.c:1522
ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2265 [inline]
ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2272 [inline]
ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1605 [inline]
ieee80211_ibss_rx_queued_mgmt+0x3ed/0x2cd0 net/mac80211/ibss.c:1638
ieee80211_iface_process_skb net/mac80211/iface.c:1679 [inline]
ieee80211_iface_work+0x726/0xc80 net/mac80211/iface.c:1733
cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:433
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 1989cd3d56e2 Linux 6.1.167
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13537f4e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=b9166ddb6029e3dd5c92
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1474e580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a8c0ce580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/814271465bd5/disk-1989cd3d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bd559379c491/vmlinux-1989cd3d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/063c12bf8ba7/bzImage-1989cd3d.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/9e75ea7a2b23/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b9166d...@syzkaller.appspotmail.com
INFO: task kworker/0:0:7 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0 state:D stack:24112 pid:7 ppid:2 flags:0x00004000
Workqueue: events_long flush_mdb
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit_lock+0xd8/0x580 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
lock_buffer include/linux/buffer_head.h:397 [inline]
hfs_mdb_commit+0x111/0x1100 fs/hfs/mdb.c:271
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
INFO: task syz-executor:4386 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21200 pid:4386 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209
__wait_on_bit_lock+0xd8/0x580 kernel/sched/wait_bit.c:90
out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117
lock_buffer include/linux/buffer_head.h:397 [inline]
hfs_mdb_commit+0xad2/0x1100 fs/hfs/mdb.c:325
hfs_sync_fs+0x11/0x20 fs/hfs/super.c:35
sync_filesystem+0xe6/0x220 fs/sync.c:56
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7c/0xe0 fs/super.c:1470
deactivate_locked_super+0x93/0xf0 fs/super.c:332
cleanup_mnt+0x42c/0x4b0 fs/namespace.c:1191
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fed6ed9da57
RSP: 002b:00007ffc9afd7568 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fed6ee32048 RCX: 00007fed6ed9da57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc9afd7620
RBP: 00007ffc9afd7620 R08: 00007ffc9afd8620 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc9afd86b0
R13: 00007fed6ee32048 R14: 0000000000024fcf R15: 00007ffc9afd86f0
</TASK>
Showing all locks held in the system:
2 locks held by kworker/0:0/7:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900000c7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2df30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e750 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
2 locks held by kworker/1:0/22:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/1:1/26:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90000a1fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by khungtaskd/28:
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d5a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/1:2/128:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002dc7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/1:3/3653:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900032b7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4029:
#0: ffff88814d3d6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by kworker/1:4/4329:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900043a7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/0:3/4333:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90004387d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/0:6/4369:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900032c7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by syz-executor/4386:
#0: ffff88807b9e40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4436:
#0: ffff888026fe40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4452:
#0: ffff88805d4b40e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4467:
#0: ffff88802a4540e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4483:
#0: ffff88802a44a0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4509:
#0: ffff88805708c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4530:
#0: ffff888078b2e0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4552:
#0: ffff888075dc80e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz-executor/4573:
#0: ffff888058f0c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
2 locks held by kworker/1:8/4582:
#0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900038f7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 46 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0x5c/0xe0 kernel/kcov.c:349
Code: 41 54 53 48 8b 0c cd 38 25 90 8a 48 8b 54 24 20 65 4c 8b 05 06 f6 7f 7e 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 <65> 44 8b 1d f4 f5 7f 7e 41 81 e3 00 01 ff 00 74 13 41 81 fb 00 01
RSP: 0018:ffffc90000b772d8 EFLAGS: 00000206
RAX: 0000000000000028 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffffffff89b31534 RSI: ffffffff8dfafde0 RDI: 0000000000000001
RBP: ffffc90000b77690 R08: ffff88801dae5940 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000000 R12: ffff88807d7f209c
R13: 0000000000000001 R14: ffff88807d7f207c R15: 000000000000000a
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a904d63168 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
_ieee802_11_parse_elems_full+0x6a4/0x3640 net/mac80211/util.c:1051
ieee802_11_parse_elems_full+0xcdc/0x1220 net/mac80211/util.c:1522
ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2265 [inline]
ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2272 [inline]
ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1605 [inline]
ieee80211_ibss_rx_queued_mgmt+0x3ed/0x2cd0 net/mac80211/ibss.c:1638
ieee80211_iface_process_skb net/mac80211/iface.c:1679 [inline]
ieee80211_iface_work+0x726/0xc80 net/mac80211/iface.c:1733
cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:433
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
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