INFO: task syz.3.1108:11663 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.3.1108 state:D stack:24536 pid:11663 tgid:11663 ppid:7943 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
vivid_fop_release+0x6c/0xaa0 drivers/media/test-drivers/vivid/vivid-core.c:645
v4l2_release+0x1af/0x370 drivers/media/v4l2-core/v4l2-dev.c:468
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 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+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9e3598f749
RSP: 002b:00007ffd918fa8a8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f9e35be7da0 RCX: 00007f9e3598f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f9e35be7da0 R08: 0000000000010e34 R09: 00000019918fab9f
R10: 00007f9e35be7cb0 R11: 0000000000000246 R12: 000000000008658e
R13: 00007ffd918fa9a0 R14: ffffffffffffffff R15: 00007ffd918fa9c0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:6/324:
#0: ffff888145ab1148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc900031d7b80 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
2 locks held by getty/5594:
#0: ffff8880345380a0 (&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
3 locks held by kworker/u8:27/7476:
#0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000c12fb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by syz.3.1108/11663:
#0: ffff88802a900448 (&mdev->req_queue_mutex){+.+.}-{4:4}, at: v4l2_release+0x152/0x370 drivers/media/v4l2-core/v4l2-dev.c:467
#1: ffff88802a905aa8 (&dev->mutex#3){+.+.}-{4:4}, at: vivid_fop_release+0x6c/0xaa0 drivers/media/test-drivers/vivid/vivid-core.c:645
1 lock held by syz.3.1108/11669:
1 lock held by syz.8.1200/12036:
#0: ffff88802a900448 (&mdev->req_queue_mutex){+.+.}-{4:4}, at: v4l2_release+0x152/0x370 drivers/media/v4l2-core/v4l2-dev.c:467
1 lock held by syz.0.1224/12121:
#0: ffff88802a900448 (&mdev->req_queue_mutex){+.+.}-{4:4}, at: v4l2_release+0x152/0x370 drivers/media/v4l2-core/v4l2-dev.c:467
1 lock held by syz.6.1251/12220:
#0: ffff88802a900448 (&mdev->req_queue_mutex){+.+.}-{4:4}, at: v4l2_release+0x152/0x370 drivers/media/v4l2-core/v4l2-dev.c:467
2 locks held by syz.9.1382/12797:
8 locks held by syz-executor/12946:
#0: ffff8880337aa420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2680 [inline]
#0: ffff8880337aa420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
#1: ffff88806a96b088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
#2: ffff88814478cd28 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88814478cd28 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
#3: ffffffff8ed9f508 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff88807a58d0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88807a58d0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
#4: ffff88807a58d0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302
#5: ffff88807a58a250 (&devlink->lock_key#18){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778
#6: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175
#7: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#7: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
1 lock held by syz.2.1460/13073:
#0: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
=============================================
NMI backtrace for cpu 0
CPU: 0 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+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 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:363 [inline]
watchdog+0xe40/0xe90 kernel/hung_task.c:557
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12347 Comm: syz.7.1280 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:unwind_get_return_address+0x8/0x90 arch/x86/kernel/unwind_orc.c:381
Code: 00 4c 89 f7 4c 89 fe e9 29 ff ff ff e8 61 83 e9 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 <53> 48 89 fb 49 be 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc900031475d0 EFLAGS: 00000202
RAX: ffffc90003147670 RBX: ffffc900031476a0 RCX: d253a214b6e62301
RDX: ffffc90003147678 RSI: dffffc0000000000 RDI: ffffc900031475e8
RBP: ffffc90003147670 R08: ffffc90003147670 R09: 0000000000000000
R10: ffffc90003147638 R11: fffff52000628ec9 R12: ffff88801d78bd00
R13: 1ffff92000628ee8 R14: ffffffff81ad9d50 R15: ffffc900031475e8
FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000600e2000 CR4: 00000000003526f0
DR0: 0000000000000003 DR1: 00000000000001f8 DR2: 000000000000008e
DR3: 000000000000057a DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
vfree+0x25a/0x400 mm/vmalloc.c:3504
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8bd/0x25b0 kernel/exit.c:971
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 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+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb55578f749
Code: Unable to access opcode bytes at 0x7fb55578f71f.
RSP: 002b:00007fb55661e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000124
RAX: 0000000000000004 RBX: 00007fb5559e5fa0 RCX: 00007fb55578f749
RDX: 0000000000080000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007fb555813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb5559e6038 R14: 00007fb5559e5fa0 R15: 00007fff44b614b8