INFO: task syz.0.65:6113 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.65 state:D stack:28568 pid:6113 tgid:6111 ppid:5952 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
bdev_release+0x1a9/0x650 block/bdev.c:1145
blkdev_release+0x15/0x20 block/fops.c:706
__fput+0x44f/0xa70 fs/file_table.c:468
task_work_run+0x1d9/0x270 kernel/task_work.c:233
get_signal+0x11eb/0x1330 kernel/signal.c:2807
arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1dfd39aeb9
RSP: 002b:00007f1dfe1da028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f1dfd616090 RCX: 00007f1dfd39aeb9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f1dfd408c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1dfd616128 R14: 00007f1dfd616090 R15: 00007ffd08adbdc8
Showing all locks held in the system:
1 lock held by khungtaskd/32:
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by klogd/5176:
#0: ffff8880b873a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
2 locks held by getty/5577:
#0: ffff88814e0350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5859:
#0: ffff8880252d2358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by udevd/5877:
#0: ffff888025387358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.0.65/6113:
#0: ffff8880252d2358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145
1 lock held by udevd/6117:
#0: ffff888025383358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.1.94/6203:
#0: ffff888025383358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145
1 lock held by udevd/6229:
#0: ffff8880252d6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.2.196/6461:
#0: ffff8880252d6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145
1 lock held by udevd/6465:
#0: ffff888025402358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.3.208/6512:
#0: ffff888025402358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145
1 lock held by syz.4.213/6549:
#0: ffff888025387358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 142 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: 0x0 (events_unbound)
RIP: 0010:preempt_count kernel/rcu/tree.c:4021 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x4/0x120 kernel/rcu/tree.c:4025
Code: 38 33 03 89 df e9 4e ff ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 41 56 53 65 8b 0d a0 bf 48 11 b0 01 f7 c1 00 00 f0 00 0f 85
RSP: 0018:ffffc90002e177a8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000003
RDX: 0000000000000000 RSI: ffffffff8c0739e0 RDI: ffffffff8c0739a0
RBP: dffffc0000000000 R08: ffffffff8fef1b77 R09: 1ffffffff1fde36e
R10: dffffc0000000000 R11: fffffbfff1fde36f R12: ffff88801dfcdb80
R13: ffffffff8e59ae60 R14: 0000000000000001 R15: ffffffff8df79dd8
FS: 0000000000000000(0000) GS:ffff8881257f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8bdbfe8600 CR3: 000000000e346000 CR4: 0000000000350ef0
Call Trace:
rcu_read_lock_held_common kernel/rcu/update.c:113 [inline]
rcu_read_lock_sched_held+0x1e/0x70 kernel/rcu/update.c:124
task_css include/linux/cgroup.h:460 [inline]
task_ca kernel/sched/cpuacct.c:41 [inline]
cpuacct_charge+0x117/0x320 kernel/sched/cpuacct.c:343
cgroup_account_cputime include/linux/cgroup.h:742 [inline]
update_se+0x2b8/0x5e0 kernel/sched/fair.c:1163
update_curr+0x76/0x4f0 kernel/sched/fair.c:1209
dequeue_entity kernel/sched/fair.c:5353 [inline]
dequeue_entities+0x1b6/0x3850 kernel/sched/fair.c:7026
dequeue_task_fair+0x1fd/0x760 kernel/sched/fair.c:7125
block_task kernel/sched/core.c:2158 [inline]
try_to_block_task kernel/sched/core.c:6491 [inline]
__schedule+0x676/0x5050 kernel/sched/core.c:6803
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
worker_thread+0xfb6/0x1360 kernel/workqueue.c:3436
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246