INFO: task syz.7.1140:11114 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1140 state:D stack:28184 pid:11114 tgid:11110 ppid:7047 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
device_lock include/linux/device.h:895 [inline]
usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x7ce/0x1420 fs/open.c:962
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:4628 [inline]
path_openat+0x340e/0x3dd0 fs/namei.c:4787
do_filp_open+0x1fa/0x410 fs/namei.c:4814
do_sys_openat2+0x121/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f348778df90
RSP: 002b:00007f348858fb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f348778df90
RDX: 0000000000000002 RSI: 00007f348858fc10 RDI: 00000000ffffff9c
RBP: 00007f348858fc10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f34879e6218 R14: 00007f34879e6180 R15: 00007f3487b0fa28
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/0:2/978:
3 locks held by kworker/1:2/981:
2 locks held by getty/5593:
#0: ffff88802fecc0a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
1 lock held by syz.7.1140/11114:
#0: ffff888027e45198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888027e45198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
2 locks held by syz.8.1658/13198:
1 lock held by syz.3.1662/13211:
2 locks held by syz.9.1664/13221:
=============================================
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 10/25/2025
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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 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: 5837 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pvclock_read_begin arch/x86/kernel/pvclock.c:119 [inline]
RIP: 0010:__pvclock_clocksource_read arch/x86/kernel/pvclock.c:76 [inline]
RIP: 0010:pvclock_clocksource_read_nowd+0x5/0xf0 arch/x86/kernel/pvclock.c:120
Code: 0e 00 f3 0f 1e fa fb f4 c3 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 <41> 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 fb 40 73 56 44 89
RSP: 0018:ffffc90000a08e90 EFLAGS: 00000006
RAX: ffffffff8168a8db RBX: ffff8880b87243c0 RCX: ffff888030425b80
RDX: 0000000000010000 RSI: ffffffff8bc083c0 RDI: ffffffff92864040
RBP: ffffc90000a08f98 R08: ffffffff8f822277 R09: 1ffffffff1f0444e
R10: dffffc0000000000 R11: fffffbfff1f0444f R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc90000a08f20 R15: 1ffff920001411e0
FS: 00007f8d8c833880(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9addb42f8 CR3: 000000001e3ec000 CR4: 00000000003526f0
Call Trace:
kvm_sched_clock_read+0x11/0x20 arch/x86/kernel/kvmclock.c:91
sched_clock+0x17/0x60 arch/x86/kernel/tsc.c:289
sched_clock_cpu+0x74/0x430 kernel/sched/clock.c:397
irqtime_account_irq+0x6e/0x1c0 kernel/sched/cputime.c:67
account_hardirq_exit include/linux/vtime.h:154 [inline]
__irq_exit_rcu+0x23/0x150 kernel/softirq.c:720
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:list_add include/linux/list.h:-1 [inline]
RIP: 0010:d_shrink_add fs/dcache.c:523 [inline]
RIP: 0010:to_shrink_list+0x166/0x2f0 fs/dcache.c:949
Code: 04 00 0f 85 fb 00 00 00 e8 b7 10 82 ff 4c 8d bb 00 01 00 00 4d 89 e6 49 c1 ee 03 43 80 3c 2e 00 74 08 4c 89 e7 e8 ca 30 e8 ff <4c> 89 e6 4d 8b 24 24 4c 89 ff 48 89 34 24 4c 89 e2 e8 14 d5 58 02
RSP: 0018:ffffc9000400f5a8 EFLAGS: 00000246
RAX: ffffffff823ee709 RBX: ffff888055a2ceb0 RCX: ffff888030425b80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff1100ab459d6 R08: ffff8880338c9c5f R09: 1ffff1100671938b
R10: dffffc0000000000 R11: ffffed100671938c R12: ffffc9000400f6d0
R13: dffffc0000000000 R14: 1ffff92000801eda R15: ffff888055a2cfb0
select_collect+0xcb/0x1a0 fs/dcache.c:1522
d_walk+0x1d7/0x780 fs/dcache.c:1345
shrink_dcache_tree+0x11a/0x2e0 fs/dcache.c:1587
shrink_dcache_parent fs/dcache.c:1616 [inline]
d_invalidate+0x11d/0x260 fs/dcache.c:1698
lookup_fast+0x3c3/0x5b0 fs/namei.c:1823
walk_component fs/namei.c:2217 [inline]
link_path_walk+0x720/0x18d0 fs/namei.c:2589
path_openat+0x2b3/0x3dd0 fs/namei.c:4783
do_filp_open+0x1fa/0x410 fs/namei.c:4814
do_sys_openat2+0x121/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8d8c0a7407
Code: 48 89 fa 4c 89 df e8 38 aa 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:00007ffeca8c8550 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8d8c833880 RCX: 00007f8d8c0a7407
RDX: 0000000000080000 RSI: 00007ffeca8c86d0 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005602b38577f5
R13: 00005602b38577f5 R14: 0000000000000001 R15: 00005602b3872140