INFO: task syz.1.4462:29549 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.1.4462 state:D stack:25608 pid:29549 tgid:29546 ppid:16761 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
device_lock include/linux/device.h:1040 [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:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce4cb5d60e
RSP: 002b:00007fce4da54b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fce4da556c0 RCX: 00007fce4cb5d60e
RDX: 0000000000000402 RSI: 00007fce4da54c00 RDI: ffffffffffffff9c
RBP: 00007fce4da54c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007fce4ce16128 R14: 00007fce4ce16090 R15: 00007fce4cf3fa48
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5379:
#0: ffff8880365770a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
6 locks held by kworker/0:16/14327:
1 lock held by syz-executor/27347:
1 lock held by syz.1.4462/29549:
#0: ffff888029c471d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff888029c471d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
1 lock held by syz.0.5049/1703:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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:162 [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:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 5612 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:min_vruntime_update kernel/sched/fair.c:978 [inline]
RIP: 0010:min_vruntime_cb_propagate kernel/sched/fair.c:1000 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:321 [inline]
RIP: 0010:rb_erase_augmented include/linux/rbtree_augmented.h:329 [inline]
RIP: 0010:rb_erase_augmented_cached include/linux/rbtree_augmented.h:340 [inline]
RIP: 0010:__dequeue_entity+0xc97/0x11b0 kernel/sched/fair.c:1017
Code: 00 49 29 1c 24 48 81 c4 90 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 4d 8b 24 24 49 83 e4 fc 0f 84 ab fe ff ff <49> 8d 6c 24 20 48 89 e9 48 c1 e9 03 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffffc900036b7850 EFLAGS: 00000086
RAX: ffff88802c940090 RBX: ffff88802c9400a0 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffff8880300c3e00 RDI: ffff8880300c3e20
RBP: 0000000000000000 R08: ffff8880b863bcdf R09: 0000000000000000
R10: ffff8880b863bcd0 R11: ffffffff819806f0 R12: ffff88802c940090
R13: ffff8880300c3e00 R14: 1ffff11005928014 R15: ffff88802c940091
FS: 0000555566a43540(0000) GS:ffff888125290000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001f5030 CR3: 0000000074e94000 CR4: 00000000003526f0
Call Trace:
set_next_entity+0x101/0x6b0 kernel/sched/fair.c:5713
set_next_task_fair+0x6b/0x1d0 kernel/sched/fair.c:13861
put_prev_set_next_task kernel/sched/sched.h:2715 [inline]
pick_next_task kernel/sched/core.c:6331 [inline]
__schedule+0x3ee5/0x5680 kernel/sched/core.c:7104
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
do_nanosleep+0x1c2/0x620 kernel/time/hrtimer.c:2293
hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2339
__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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe776757f57
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:00007ffd59be8880 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000555566a43540 RCX: 00007fe776757f57
RDX: 00007ffd59be88c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd59be8da0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffd59be88fc R14: 00007ffd59be8990 R15: 0000000000000000