INFO: task syz.0.6168:25670 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.0.6168 state:D stack:28584 pid:25670 tgid:25669 ppid:24327 task_flags:0x400040 flags:0x08080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
device_lock include/linux/device.h:1109 [inline]
usbdev_open+0x151/0x760 drivers/usb/core/devio.c:1054
chrdev_open+0x4d9/0x600 fs/char_dev.c:413
do_dentry_open+0x80e/0x1360 fs/open.c:1000
vfs_open_consume+0x4a/0x350 fs/open.c:1131
do_open fs/namei.c:4845 [inline]
path_openat+0x16fc/0x20f0 fs/namei.c:5010
do_file_open+0x23e/0x4a0 fs/namei.c:5039
do_sys_openat2+0x115/0x200 fs/open.c:1442
do_sys_open fs/open.c:1448 [inline]
__do_compat_sys_openat fs/open.c:1510 [inline]
__se_compat_sys_openat fs/open.c:1508 [inline]
__ia32_compat_sys_openat+0x131/0x160 fs/open.c:1508
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
do_int80_emulation+0x198/0x500 arch/x86/entry/syscall_32.c:166
asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:598
RIP: 0023:0xf71c77ab
RSP: 002b:00000000f548603c EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f5486100
RDX: 0000000000080402 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
locks held by kworker/u8:0/12: 5, last CPU#1:
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90000117c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{
#1: ffffc90000117c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90000117c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90000117c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90000117c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffffffff8fde60d0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_disable+0x12/0x20 kernel/jump_label.c:247
#3: ffffffff9003c6e0 (jump_label_mutex){+.+.}-{4:4}, at: jump_label_lock kernel/jump_label.c:27 [inline]
#3: ffffffff9003c6e0 (jump_label_mutex){+.+.}-{4:4}, at: static_key_disable_cpuslocked+0x8d/0x1a0 kernel/jump_label.c:238
#4: ffffffff8fdfd120 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
locks held by pr/ttyS0/32: 1, last CPU#0:
#0: ffffffff8fe33e18 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8fe33e18 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:493 [inline]
#0: ffffffff8fe33e18 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
locks held by khungtaskd/33: 1, last CPU#0:
#0: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5393: 2, on CPU#1:
#0: ffff8880369c20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/18995: 4, on CPU#0:
#0: ffff88803d250e18 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
#1: ffff88807ce8e080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
#2: ffff888037398b48 (kn->active#30){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888037398b48 (kn->active#30){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
#3: ffff8880298631d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1114 [inline]
#3: ffff8880298631d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by kworker/0:17/21177: 6, on CPU#0:
#0: ffff8880236dd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8880236dd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8880236dd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff8880236dd948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90004517c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004517c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004517c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90004517c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#2: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917
#3: ffff8880298631d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#3: ffff8880298631d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1106
#4: ffff8880792981a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#4: ffff8880792981a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1106
#5: ffffffff8fdf44a8 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2b0 kernel/umh.c:212
locks held by kworker/u8:12/21709: 3, last CPU#1:
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe0c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90006fc7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90006fc7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90006fc7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90006fc7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88802aba2258 (&devlink->lock_key#13){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834
locks held by syz.0.6168/25670: 1, on CPU#0:
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x760 drivers/usb/core/devio.c:1054
locks held by syz.6.6347/26322: 1, on CPU#0:
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x760 drivers/usb/core/devio.c:1054
locks held by syz.3.6589/27184: 1, on CPU#1:
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x760 drivers/usb/core/devio.c:1054
locks held by syz.4.6729/27665: 1, on CPU#0:
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1109 [inline]
#0: ffff88802acab1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x760 drivers/usb/core/devio.c:1054
locks held by syz.9.6787/27875: 2, last CPU#1:
#0: ffff88807cfc7180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline]
#0: ffff88807cfc7180 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
locks held by syz.7.6791/27894: 2, last CPU#1:
#0: ffff88802bb00340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline]
#0: ffff88802bb00340 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:685
locks held by syz.7.6791/27897: 1, on CPU#1:
#0: ffff88802bb00340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:595
locks held by syz.7.6791/27896: 2, last CPU#1:
#0: ffff88802bb00f80 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:586 [inline]
#0: ffff88802bb00f80 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ff5a360 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 33 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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+0xfd2/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 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: 32 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:425
Code: e8 6e ad 47 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 0f 1b be fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000a878b8 EFLAGS: 00000002
RAX: 1ffffffff37fc100 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85815ef0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9bfe0ee0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812362d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f53c3ff4 CR3: 00000000441aa000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:134 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2036
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3294 [inline]
__serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3369
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3520
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 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