INFO: task syz.2.1106:10052 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.2.1106 state:D stack:28120 pid:10052 tgid:10048 ppid:5651 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__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+0x822/0x13a0 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+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc33a55d68e
RSP: 002b:00007fc3387d4b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc3387d56c0 RCX: 00007fc33a55d68e
RDX: 0000000000000002 RSI: 00007fc3387d4c00 RDI: ffffffffffffff9c
RBP: 00007fc3387d4c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007fc33a816218 R14: 00007fc33a816180 R15: 00007fc33a93fa48
Showing all locks held in the system:
2 locks held by ksoftirqd/0/15:
#0: ffff8880b863b0e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:660
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
1 lock held by khungtaskd/30:
#0: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:1/46:
#0: ffff8880226ce940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff8880226ce940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90000b67c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90000b67c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffff88802addf1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802addf1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff888031bc91d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff888031bc91d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#4: ffff8880202b91a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff8880202b91a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#5: ffffffff8e7f9a68 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214
4 locks held by kworker/u8:5/78:
#0: ffff8880b863b0e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:660
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117
#3: ffffffff9a710440 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x83/0x580 lib/debugobjects.c:845
5 locks held by kworker/1:2/3109:
#0: ffff8880226ce940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff8880226ce940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000d757c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000d757c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffff88802ac7f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802ac7f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff888029abf1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff888029abf1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#4: ffff888053a841a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff888053a841a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
2 locks held by getty/5389:
#0: ffff8880365df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
4 locks held by udevd/5778:
#0: ffff888056804518 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
#1: ffff888055cce080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff88805852ee18 (kn->active#31){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88805852ee18 (kn->active#31){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff888031bc91d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline]
#3: ffff888031bc91d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by kworker/u8:10/8311:
#0: ffff88801e3b2940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801e3b2940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90005d3fc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90005d3fc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
1 lock held by syz.2.1106/10052:
#0: ffff88802addf1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802addf1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
1 lock held by syz.3.1175/10288:
#0: ffff88802addf1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802addf1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
3 locks held by kworker/0:15/10589:
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000d787c40 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000d787c40 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8e963028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#2: ffffffff8e963028 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
=============================================
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 05/09/2026
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+0x389/0x470 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: 48 Comm: kworker/u8:3 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:get_stack_info_noinstr+0xf7/0x130 arch/x86/kernel/dumpstack_64.c:189
Code: d7 40 0f 92 c6 49 39 cf 40 0f 93 c7 40 08 f7 75 27 41 c7 06 02 00 00 00 49 89 56 08 49 89 4e 10 48 8b 00 49 89 46 18 89 d8 5b <41> 5c 41 5d 41 5e 41 5f e9 3c 2b 03 00 cc 4c 89 ff 4c 89 f6 5b 41
RSP: 0018:ffffc90000b874d0 EFLAGS: 00000202
RAX: 0000000000b87501 RBX: ffffc90000b875a8 RCX: ffffc90000b80000
RDX: ffffc90000b87588 RSI: ffffc90000b88000 RDI: ffffc90000b87528
RBP: ffffc90000b87501 R08: ffffc90000b87501 R09: 0000000000000000
R10: ffffc90000b87588 R11: fffff52000170ebd R12: ffff88801af35d00
R13: ffffc90000b875a8 R14: ffffc90000b87588 R15: ffffc90000b87528
FS: 0000000000000000(0000) GS:ffff8881252a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3ce067 CR3: 000000000e74a000 CR4: 00000000003526f0
DR0: 0000000000000006 DR1: 0000000000000000 DR2: 000000007fffdff5
DR3: 0000800000000005 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
get_stack_info+0x3a/0xf0 arch/x86/kernel/dumpstack_64.c:199
__unwind_start+0x43e/0x760 arch/x86/kernel/unwind_orc.c:756
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5296 [inline]
__kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5408
kmalloc_reserve net/core/skbuff.c:635 [inline]
__alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713
alloc_skb include/linux/skbuff.h:1385 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x29a/0xb90 drivers/net/netdevsim/dev.c:922
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 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