INFO: task syz.6.5486:27236 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.6.5486 state:D stack:27456 pid:27236 tgid:27235 ppid:24662 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: 0033:0x7f914a58df90
RSP: 002b:00007f914b4d3b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000008401 RCX: 00007f914a58df90
RDX: 0000000000008401 RSI: 00007f914b4d3c10 RDI: 00000000ffffff9c
RBP: 00007f914b4d3c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f914a7e6038 R14: 00007f914a7e5fa0 R15: 00007f914a90fa28
Showing all locks held in the system:
6 locks held by kworker/u8:1/13:
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
2 locks held by getty/5587:
#0: ffff88802fbc70a0 (&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
5 locks held by kworker/1:3/15683:
3 locks held by kworker/u8:17/17785:
1 lock held by syz.6.5486/27236:
#0: ffff888028975198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888028975198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.0.5825/28448:
#0: ffff888028975198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888028975198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
1 lock held by syz.5.5838/28503:
#0: ffff888028975198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888028975198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x16e/0x760 drivers/usb/core/devio.c:1054
2 locks held by syz.7.5928/28960:
2 locks held by syz.7.5930/28970:
3 locks held by syz.2.5935/28992:
1 lock held by syz.9.5937/28994:
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline]
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:579
1 lock held by syz.9.5937/28995:
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline]
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: do_mlock+0x165/0x720 mm/mlock.c:630
1 lock held by syz.9.5937/28996:
1 lock held by syz.9.5937/29000:
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: do_mbind mm/mempolicy.c:1530 [inline]
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: kernel_mbind mm/mempolicy.c:1752 [inline]
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: __do_sys_mbind mm/mempolicy.c:1826 [inline]
#0: ffff888028eb0340 (&mm->mmap_lock){++++}-{4:4}, at: __se_sys_mbind+0x630/0xc40 mm/mempolicy.c:1822
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5815 Comm: syz-executor 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:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:217
Code: 5b e9 83 fc 5a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 10 80 92 <65> 8b 15 68 1a bf 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc90003f4f938 EFLAGS: 00000046
RAX: ffffffff8165b807 RBX: ffff8880278355f6 RCX: ffff888031af0000
RDX: 0000000040000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff888027833d07 R09: 1ffff11004f067a0
R10: dffffc0000000000 R11: ffffed1004f067a1 R12: 0000000000080000
R13: ffff888027833d00 R14: dffffc0000000000 R15: 0000000000080000
FS: 0000555591b4e500(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056233f10f158 CR3: 000000007b9da000 CR4: 00000000003526f0
Call Trace:
arch_static_branch_jump arch/x86/include/asm/jump_label.h:47 [inline]
switch_to_extra arch/x86/kernel/process.h:26 [inline]
__switch_to+0x5f7/0x1480 arch/x86/kernel/process_64.c:676
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
do_nanosleep+0x1c5/0x610 kernel/time/hrtimer.c:2116
hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2163
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline]
__se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375
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: 0033:0x7f176d9c1fc3
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 9e 95 1f 00 00 74 14 b8 e6 00 00 00 0f 05 d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007ffe6d148e28 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f176d9c1fc3
RDX: 00007ffe6d148e40 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 7fffffffffffffff R09: 3fffffffffffffff
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe6d149290
R13: 0000000000000004 R14: 00007ffe6d148e7c R15: 00007ffe6d148f10