INFO: task syz.5.2738:16838 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.5.2738 state:D stack:28160 pid:16838 tgid:16825 ppid:8647 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
device_lock include/linux/device.h:895 [inline]
usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 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+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f00c9f5cfce
RSP: 002b:00007f00cad99b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f00cad9a6c0 RCX: 00007f00c9f5cfce
RDX: 0000000000000000 RSI: 00007f00cad99c00 RDI: ffffffffffffff9c
RBP: 00007f00cad99c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f00ca216128 R14: 00007f00ca216090 R15: 00007f00ca33fa48
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/1:2/796:
2 locks held by getty/5583:
#0: ffff888034fa30a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz.5.2738/16838:
#0: ffff888028f9c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888028f9c198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
=============================================
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 02/12/2026
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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 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: 5812 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:arch_atomic64_add arch/x86/include/asm/atomic64_64.h:-1 [inline]
RIP: 0010:raw_atomic64_add include/linux/atomic/atomic-arch-fallback.h:2672 [inline]
RIP: 0010:raw_atomic_long_add include/linux/atomic/atomic-long.h:121 [inline]
RIP: 0010:atomic_long_add include/linux/atomic/atomic-instrumented.h:3261 [inline]
RIP: 0010:update_tg_load_avg kernel/sched/fair.c:4185 [inline]
RIP: 0010:__update_blocked_fair kernel/sched/fair.c:9914 [inline]
RIP: 0010:__sched_balance_update_blocked_averages+0x4e6/0xf40 kernel/sched/fair.c:10015
Code: c5 74 08 4c 89 e7 e8 f9 5d 96 00 4d 8b 24 24 49 8d bc 24 40 01 00 00 be 08 00 00 00 e8 83 60 96 00 f0 4d 01 ac 24 40 01 00 00 <48> 8b 44 24 48 80 3c 28 00 4c 8b 64 24 50 74 08 4c 89 e7 e8 c2 5d
RSP: 0018:ffffc90000a08df8 EFLAGS: 00000007
RAX: dffffc0000000001 RBX: ffff88806ab96948 RCX: ffffffff81997a1d
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88806abedb40
RBP: dffffc0000000000 R08: ffff88806abedb47 R09: 1ffff1100d57db68
R10: dffffc0000000000 R11: ffffed100d57db69 R12: ffff88806abeda00
R13: ffffffffffffffd1 R14: 1ffff1100d572d28 R15: ffff88806ab96988
FS: 000055557dcd1540(0000) GS:ffff888125564000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff569edaf8 CR3: 0000000075000000 CR4: 00000000003526f0
Call Trace:
sched_balance_update_blocked_averages+0x129/0x250 kernel/sched/fair.c:10028
sched_balance_softirq+0xe1/0x1a0 kernel/sched/fair.c:13094
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
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:finish_task_switch+0x245/0x920 kernel/sched/core.c:5152
Code: 00 00 48 85 db 0f 85 e8 01 00 00 e9 56 05 00 00 4c 8b 75 d0 49 83 c4 48 4c 89 e7 e8 a5 2d 1b 0a e8 20 8c 38 00 fb 4c 8b 65 c0 <49> 8d bc 24 70 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900039b7958 EFLAGS: 00000206
RAX: 00000000002cdca9 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8def3648 RDI: ffffffff8c27b080
RBP: ffffc900039b79b0 R08: ffffffff901190b7 R09: 1ffffffff2023216
R10: dffffc0000000000 R11: fffffbfff2023217 R12: ffff888077e39e80
R13: dffffc0000000000 R14: ffff88801f6d9e80 R15: ffff8880b873b918
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15e5/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
do_nanosleep+0x1c2/0x620 kernel/time/hrtimer.c:2124
hrtimer_nanosleep+0x188/0x390 kernel/time/hrtimer.c:2171
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline]
__se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1368
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ebb957917
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:00007ffe9e079190 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000055557dcd1540 RCX: 00007f8ebb957917
RDX: 00007ffe9e0791d0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe9e0796b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffe9e07920c R14: 00007ffe9e0792a0 R15: 0000000000000000