INFO: task syz.2.221:6749 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.2.221 state:D stack:27576 pid:6749 tgid:6746 ppid:5807 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe4/0x5e10 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
device_lock include/linux/device.h:895 [inline]
usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x73e/0x1570 fs/open.c:962
vfs_open+0x82/0x3f0 fs/open.c:1094
do_open fs/namei.c:4637 [inline]
path_openat+0x21dc/0x3120 fs/namei.c:4796
do_filp_open+0x1f7/0x420 fs/namei.c:4823
do_sys_openat2+0x12e/0x220 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+0x12d/0x210 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b9255b78e
RSP: 002b:00007f1b934c3b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1b934c46c0 RCX: 00007f1b9255b78e
RDX: 000000000000a401 RSI: 00007f1b934c3c00 RDI: ffffffffffffff9c
RBP: 00007f1b934c3c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f1b92816218 R14: 00007f1b92816180 R15: 00007ffe5f392758
Showing all locks held in the system:
6 locks held by kworker/0:0/9:
#0: ffff88801eac8d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc900000e7c98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888142ffe198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888142ffe198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888143359518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff888143359518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff888143359518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff888143359518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff888143359518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
#4: ffff88802a220e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff88802a220e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff88802a220e68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff88802a220e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
#5: ffffffff8f995e30 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x1a5/0x1c60 drivers/usb/core/hub.c:3067
1 lock held by khungtaskd/31:
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
1 lock held by klogd/5168:
#0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
2 locks held by getty/5566:
#0: ffff8880375650a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
6 locks held by kworker/0:6/5964:
#0: ffff88801eac8d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc900043ffc98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888142f5e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888142f5e198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff88807925a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88807925a198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#4: ffff88802d5b0160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88802d5b0160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008
#5: ffffffff8e48dbf0 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xab/0x250 kernel/umh.c:214
4 locks held by udevd/6123:
#0: ffff88807deca8b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:182
#1: ffff888057c99c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
#2: ffff8880594221e8 (kn->active#22){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880594221e8 (kn->active#22){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
#3: ffff88807925a198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
#3: ffff88807925a198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz.2.221/6749:
#0: ffff888142f5e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888142f5e198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054
3 locks held by kworker/u8:10/7071:
#0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
#1: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2b6f/0x5e10 kernel/sched/core.c:6861
#2: ffff8880b84262d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x124/0x1d0 kernel/time/timer.c:1004
1 lock held by syz.1.298/7102:
#0: ffff888142f5e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#0: ffff888142f5e198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054
3 locks held by syz.6.731/8833:
#0: ffffffff903f3168 (rtnl_mutex){+.+.}-{4:4}, at: bpf_xdp_link_release+0x1f/0x7b0 net/core/dev.c:10527
#1: ffffffff903f8a88 (bpf_dispatcher_xdp.mutex){+.+.}-{4:4}, at: bpf_dispatcher_change_prog+0x38/0xa60 kernel/bpf/dispatcher.c:146
#2: ffffffff8e5efab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
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 01/24/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 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: 8825 Comm: syz.3.730 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x70 kernel/kcov.c:235
Code: f3 0f 1e fa 65 8b 05 c5 54 dd 11 48 8b 34 24 65 48 8b 15 a1 54 dd 11 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 91 f4 72 09 8b 82 6c 16 00 00 85 c0 74 f1 8b 82 48 16 00 00 83
RSP: 0018:ffffc9000be572b0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea0001766180 RCX: ffffffff8267f7f8
RDX: ffff88802d2124c0 RSI: ffffffff8267f806 RDI: ffff88802d2124c0
RBP: dffffc0000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000178
R13: ffff8880314b8bd0 R14: ffffea0001766181 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881245db000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0e35e1198 CR3: 0000000012631000 CR4: 00000000003526f0
Call Trace:
arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline]
page_fixed_fake_head include/linux/page-flags.h:210 [inline]
_compound_head include/linux/page-flags.h:288 [inline]
free_pages_and_swap_cache+0x156/0x480 mm/swap_state.c:345
__tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:137
tlb_batch_pages_flush mm/mmu_gather.c:150 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:398 [inline]
tlb_flush_mmu+0xe9/0x590 mm/mmu_gather.c:405
zap_pte_range mm/memory.c:1897 [inline]
zap_pmd_range mm/memory.c:1950 [inline]
zap_pud_range mm/memory.c:1978 [inline]
zap_p4d_range mm/memory.c:1999 [inline]
unmap_page_range+0x2219/0x43e0 mm/memory.c:2020
unmap_single_vma+0x153/0x240 mm/memory.c:2062
unmap_vmas+0x218/0x470 mm/memory.c:2104
exit_mmap+0x181/0xae0 mm/mmap.c:1277
__mmput+0x12a/0x410 kernel/fork.c:1173
mmput+0x67/0x80 kernel/fork.c:1196
exit_mm kernel/exit.c:581 [inline]
do_exit+0x78a/0x2a30 kernel/exit.c:959
do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x86/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd30f39aeb9
Code: Unable to access opcode bytes at 0x7fd30f39ae8f.
RSP: 002b:00007fd3101c60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd30f615fa8 RCX: 00007fd30f39aeb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd30f615fa8
RBP: 00007fd30f615fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd30f616038 R14: 00007ffc7892f410 R15: 00007ffc7892f4f8