INFO: task syz.0.1899:13637 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1899 state:D stack:28792 pid:13637 tgid:13636 ppid:5808 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
bdev_open+0x41a/0xe40 block/bdev.c:961
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4677 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4836
do_file_open+0x20e/0x430 fs/namei.c:4865
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbf2b15d04e
RSP: 002b:00007fbf2bfc0b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbf2bfc16c0 RCX: 00007fbf2b15d04e
RDX: 0000000000002000 RSI: 00007fbf2bfc0c00 RDI: ffffffffffffff9c
RBP: 00007fbf2bfc0c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007fbf2b416038 R14: 00007fbf2b415fa0 R15: 00007ffcb19c42f8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e77a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e77a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e77a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5568:
#0: ffff888038fe10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by udevd/6507:
#0: ffff888027e20358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
3 locks held by kworker/u8:12/9859:
#0: ffff88813fea4148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3263
#1: ffffc90005b1fd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3264
#2: ffffffff906145a8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
1 lock held by syz.0.1899/13637:
#0: ffff888027e20358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
2 locks held by syz.4.2364/15689:
#0: ffffffff906145a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff906145a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
#1: ffffffff8e7f32f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5792 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63
Code: c6 20 1e 1b 8c 48 c7 c7 60 1e 1b 8c e9 f9 fe ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 a0 1e 1b 8c e9 cd fe ff ff 66 2e 0f
RSP: 0018:ffffc90003d57a28 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8e7e76e0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8e7e76e0 RDI: ffffffff8de5501e
RBP: ffff8880393ec980 R08: 00000000000016a0 R09: ffffed100727d930
R10: ffff8880393ec987 R11: 0000000000000000 R12: 00000000ffffffff
R13: 0000000000000046 R14: ffff8880393ed500 R15: 0000000000000001
FS: 000055557f3e0540(0000) GS:ffff888124438000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056509c7feda8 CR3: 000000007da54000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_is_held_type+0xca/0x140 kernel/locking/lockdep.c:5941
lock_is_held include/linux/lockdep.h:249 [inline]
rcu_read_lock_sched_held kernel/rcu/update.c:126 [inline]
rcu_read_lock_sched_held+0x40/0x70 kernel/rcu/update.c:120
task_css_set include/linux/cgroup.h:447 [inline]
task_dfl_cgroup include/linux/cgroup.h:516 [inline]
task_psi_group kernel/sched/psi.c:889 [inline]
task_psi_group kernel/sched/psi.c:885 [inline]
psi_account_irqtime+0x88e/0xc70 kernel/sched/psi.c:1021
__schedule+0x5fd/0x6120 kernel/sched/core.c:6904
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
do_nanosleep+0x206/0x560 kernel/time/hrtimer.c:2125
hrtimer_nanosleep+0x156/0x360 kernel/time/hrtimer.c:2172
common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1345
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline]
__se_sys_clock_nanosleep kernel/time/posix-timers.c:1368 [inline]
__x64_sys_clock_nanosleep+0x336/0x480 kernel/time/posix-timers.c:1368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5376757997
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff6ad44d60 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000055557f3e0540 RCX: 00007f5376757997
RDX: 00007fff6ad44da0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff6ad45280 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007fff6ad44ddc R14: 00007fff6ad44e70 R15: 0000000000000000