INFO: task syz.4.4066:15567 blocked for more than 143 seconds.
Not tainted 6.16.0-rc5-next-20250708-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.4066 state:D stack:27672 pid:15567 tgid:15566 ppid:7843 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5314 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
__schedule_loop kernel/sched/core.c:6775 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6790
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6847
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
sync_bdevs+0x1ac/0x340 block/bdev.c:1288
ksys_sync+0xb9/0x150 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc9df8e929
RSP: 002b:00007fdc9ee56038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fdc9e1b5fa0 RCX: 00007fdc9df8e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fdc9e1b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdc9e1b5fa0 R15: 00007ffc426f6fc8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53bfa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53bfa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53bfa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5613:
#0: ffff888034ad00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/6855:
#0: ffff888143f54358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.4.4066/15567:
#0: ffff888143f54358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288
1 lock held by udevd/16816:
5 locks held by kworker/u8:3/19152:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-next-20250708-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.16.0-rc5-next-20250708-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:mark_lock+0x9b/0x190 kernel/locking/lockdep.c:4734
Code: 00 75 19 90 48 c7 c7 86 4f e7 8d 48 c7 c6 25 97 d6 8d e8 38 ac e5 ff 90 0f 0b 90 90 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 <85> 69 60 74 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49
RSP: 0018:ffffc90000ac74f0 EFLAGS: 00000006
RAX: 0000000000000001 RBX: 0000000000000006 RCX: ffffffff9390f080
RDX: 0000000000000006 RSI: ffff8881404ea9e0 RDI: ffff8881404e9e00
RBP: 0000000000000040 R08: 0000000000000000 R09: ffffffff8211725e
R10: dffffc0000000000 R11: fffff94000010cd9 R12: 0000000000000003
R13: 0000000000000003 R14: ffff8881404ea9e0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812579f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6690182178 CR3: 000000000e336000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:-1 [inline]
__lock_acquire+0x9e2/0xd20 kernel/locking/lockdep.c:5194
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
__pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:401
get_locked_pte include/linux/mm.h:2720 [inline]
__text_poke+0x2e6/0xa10 arch/x86/kernel/alternative.c:2505
text_poke arch/x86/kernel/alternative.c:2590 [inline]
smp_text_poke_batch_finish+0xd0a/0x1100 arch/x86/kernel/alternative.c:2979
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:855
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245