INFO: task syz.3.987:10274 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.987 state:D stack:27656 pid:10274 ppid:5786 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
sync_bdevs+0x1af/0x330 block/bdev.c:1059
ksys_sync+0xba/0x150 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7b94b8eba9
RSP: 002b:00007f7b95964038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f7b94dd6090 RCX: 00007f7b94b8eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f7b94dd6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b94dd6128 R14: 00007f7b94dd6090 R15: 00007ffd3717c248
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
5 locks held by kworker/0:2/787:
2 locks held by getty/5551:
#0: ffff88802ced60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by kworker/0:3/5778:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004397d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004397d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by udevd/5796:
#0: ffff8880218a54c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
1 lock held by syz.3.987/10274:
#0: ffff8880218a54c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1af/0x330 block/bdev.c:1059
2 locks held by syz-executor/10443:
#0: ffff8880591440e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880591440e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880591440e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffffffff8cd35df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd35df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1125 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4266 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4292 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0x228/0x760 kernel/locking/lockdep.c:4359
Code: 00 00 45 31 ed 49 83 fd 31 73 67 4c 89 e0 48 c1 e8 03 0f b6 04 10 84 c0 75 76 41 8b 47 20 a9 00 00 04 00 74 2f 25 00 00 03 00 <83> f8 01 ba 03 00 00 00 83 da 00 48 8b 7c 24 10 4c 89 fe e8 30 f1
RSP: 0018:ffffc900048bf720 EFLAGS: 00000006
RAX: 0000000000010000 RBX: ffff8880236b28d8 RCX: ffffffff8167bd44
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff90da7510
RBP: ffffc900048bf7c8 R08: ffffffff90da7517 R09: 1ffffffff21b4ea2
R10: dffffc0000000000 R11: fffffbfff21b4ea3 R12: ffff8880236b2950
R13: 0000000000000002 R14: 1ffff110046d651b R15: ffff8880236b2930
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffec8e67fe8 CR3: 000000000cb30000 CR4: 00000000003526f0
Call Trace:
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
__text_poke+0x871/0xb20 arch/x86/kernel/alternative.c:2096
text_poke arch/x86/kernel/alternative.c:2121 [inline]
text_poke_bp_batch+0x4e4/0x930 arch/x86/kernel/alternative.c:2454
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293