INFO: task syz.2.5812:26194 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.5812 state:D stack:28536 pid:26194 tgid:26193 ppid:16705 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
bdev_open+0x41a/0xe40 block/bdev.c:962
blkdev_open+0x34e/0x4f0 block/fops.c:698
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: 0033:0x7f499935b58e
RSP: 002b:00007f499a1ccb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f499a1cd6c0 RCX: 00007f499935b58e
RDX: 0000000000000000 RSI: 00007f499a1ccc00 RDI: ffffffffffffff9c
RBP: 00007f499a1ccc00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f4999616038 R14: 00007f4999615fa0 R15: 00007ffd3fe935f8
Showing all locks held in the system:
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
2 locks held by getty/5570:
#0: ffff888032a4a0a0 (&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
5 locks held by kworker/1:1/11226:
#0: ffff888142afa148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9000c05fc98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff8881437c5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff8881437c5198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888143b10518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff888143b10518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff888143b10518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff888143b10518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff888143b10518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
#4: ffff888141bd0568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff888141bd0568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff888141bd0568 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff888141bd0568 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
1 lock held by udevd/12430:
#0: ffff8881417a3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
3 locks held by kworker/0:0/17484:
#0: ffff88813fe51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc900033e7c98 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff8e5ef980 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816
1 lock held by udevd/18740:
#0: ffff8881417a7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
1 lock held by syz.2.5812/26194:
#0: ffff8881417a7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:962
1 lock held by syz-executor/26727:
#0: ffffffff8e5efab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.0.6323/28298:
#0: ffffffff8e5ef980 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816
1 lock held by syz.4.6324/28302:
1 lock held by syz.5.6326/28309:
#0: ffffffff8e5ef980 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3816
1 lock held by syz.3.6327/28312:
=============================================
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 01/13/2026
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: 28312 Comm: syz.3.6327 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:__lock_acquire+0x610/0x2630 kernel/locking/lockdep.c:5234
Code: 66 25 ff 1f 0f b7 c0 48 0f a3 05 6b 19 08 14 0f 83 35 0b 00 00 48 8d 04 80 48 8d 04 80 48 8d 04 c5 60 1a eb 95 48 83 78 40 00 <0f> 84 7a 0b 00 00 8b 43 20 25 00 80 04 00 3d 00 00 04 00 0f 84 03
RSP: 0018:ffffc900051e76c0 EFLAGS: 00000082
RAX: ffffffff95eb1a60 RBX: ffff88802dbd0b30 RCX: 0000000000000000
RDX: 0000000076153240 RSI: 00000000b755b505 RDI: 00000000ffffbe79
RBP: ffff88802dbd0000 R08: 0000000048aa0974 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 3df1592f76153240
FS: 0000000000000000(0000) GS:ffff8881245dc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87f15a1000 CR3: 000000000e392000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
__debug_check_no_obj_freed lib/debugobjects.c:1088 [inline]
debug_check_no_obj_freed+0x1c9/0x630 lib/debugobjects.c:1129
free_pages_prepare mm/page_alloc.c:1440 [inline]
__free_frozen_pages+0x358/0x1130 mm/page_alloc.c:2973
vfree.part.0+0x12b/0x9d0 mm/vmalloc.c:3466
vfree+0x55/0x80 mm/vmalloc.c:3443
kcov_put kernel/kcov.c:439 [inline]
kcov_put kernel/kcov.c:435 [inline]
kcov_close+0x34/0x60 kernel/kcov.c:535
__fput+0x3ff/0xb40 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x829/0x2a30 kernel/exit.c:971
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: 0033:0x7f07fa99acb9
Code: Unable to access opcode bytes at 0x7f07fa99ac8f.
RSP: 002b:00007f07fb8cc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f07fac15fa0 RCX: 00007f07fa99acb9
RDX: 00002000000002c0 RSI: 0000000000004c0a RDI: 0000000000000003
RBP: 00007f07faa08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f07fac16038 R14: 00007f07fac15fa0 R15: 00007ffc4207a9c8