INFO: task syz.0.4209:21404 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.4209 state:D stack:26504 pid:21404 tgid:21403 ppid:16909 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747
bdev_open+0xe0/0xd30 block/bdev.c:945
blkdev_open+0x3a8/0x510 block/fops.c:676
do_dentry_open+0xdf0/0x1970 fs/open.c:964
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:3896 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4055
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
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: 0033:0x7fbf8338d290
RSP: 002b:00007fbf842a1b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000044000 RCX: 00007fbf8338d290
RDX: 0000000000044000 RSI: 00007fbf842a1c10 RDI: 00000000ffffff9c
RBP: 00007fbf842a1c10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 0000000000000000 R14: 00007fbf835b5fa0 R15: 00007fff7b9070c8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by syslogd/5186:
#0: ffff8880b8639e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:614
#1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x318/0x6d0 kernel/sched/psi.c:975
2 locks held by getty/5595:
#0: ffff888030e5a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/12233:
#0: ffff888025109358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.0.4209/21404:
#0: ffff888025109358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:464
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-rc6-syzkaller-00037-ge2291551827f #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:lookup_object lib/debugobjects.c:423 [inline]
RIP: 0010:debug_object_deactivate+0xd5/0x250 lib/debugobjects.c:875
Code: 4c 89 ff e8 ed 9a 60 fd 4d 8b 3f 45 31 f6 eb 06 4d 8b 3f 41 ff c6 4d 85 ff 74 36 4d 8d 6f 18 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 c1 9a 60 fd 4d 39 65 00 74 29 4c 89 f8 48 c1 e8
RSP: 0018:ffffc90000ac7370 EFLAGS: 00000046
RAX: 1ffff11003fff83b RBX: ffffffff99cefb28 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000ac7260
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000158e4c R12: ffff8880b863a848
R13: ffff88801fffc1d8 R14: 000000000000001e R15: ffff88801fffc1c0
FS: 0000000000000000(0000) GS:ffff888125c4f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff4049f6a0 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490
remove_hrtimer kernel/time/hrtimer.c:1156 [inline]
hrtimer_try_to_cancel+0x2ff/0x420 kernel/time/hrtimer.c:1365
update_curr_dl_se+0x1ef/0x980 kernel/sched/deadline.c:1530
update_curr+0x3ba/0x8b0 kernel/sched/fair.c:1260
dequeue_entity+0x27/0x1690 kernel/sched/fair.c:5462
dequeue_entities+0x1fa/0x1510 kernel/sched/fair.c:7094
dequeue_task_fair+0x205/0x580 kernel/sched/fair.c:7193
block_task kernel/sched/core.c:2149 [inline]
try_to_block_task kernel/sched/core.c:6619 [inline]
__schedule+0x5a7/0x4cb0 kernel/sched/core.c:6735
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
toggle_allocation_gate+0x159/0x240 mm/kfence/core.c:852
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245