INFO: task syz.0.187:6832 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.187 state:D stack:28120 pid:6832 tgid:6831 ppid:6344 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 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 bdev_release+0x1a9/0x650 block/bdev.c:1136 blkdev_release+0x15/0x20 block/fops.c:705 __fput+0x44f/0xa60 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2809 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcd6539c629 RSP: 002b:00007fcd6629f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fcd65615fa0 RCX: 00007fcd6539c629 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007fcd65432b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcd65616038 R14: 00007fcd65615fa0 R15: 00007ffe39fe8f78 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: #0: ffff88813fe7c940 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe7c940 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90000ac7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90000ac7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 2 locks held by getty/5375: #0: ffff888035b2f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by udevd/6134: #0: ffff888026dff350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 1 lock held by udevd/6153: #0: ffff888026d2f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 1 lock held by syz.0.187/6832: #0: ffff888026d2f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1136 1 lock held by udevd/6872: #0: ffff888026dfb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 1 lock held by syz.1.217/6938: #0: ffff888026dfb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1136 1 lock held by syz.2.331/7241: #0: ffff888026dff350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1136 1 lock held by modprobe/7249: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x388/0x470 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: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__lock_acquire+0x37/0x2cf0 kernel/locking/lockdep.c:5090 Code: e8 00 00 00 65 48 8b 05 57 4d 97 11 48 89 84 24 e0 00 00 00 65 48 8b 05 2f 4d 97 11 48 89 44 24 08 31 ed 83 3d d9 28 8f 0e 00 <0f> 84 ef 13 00 00 45 89 cf 49 89 f9 48 8b 07 48 3d 80 d3 fc 93 0f RSP: 0018:ffffc90000ac74f0 EFLAGS: 00000002 RAX: ffff8880206a1ec0 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88813fe72618 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff940000112a9 R12: 0000000000000000 R13: ffff88813fe72618 R14: 0000000000000001 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff888125290000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f67be3f2e9c CR3: 000000000e74a000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404 __text_poke+0x2d3/0x9a0 arch/x86/kernel/alternative.c:2587 text_poke arch/x86/kernel/alternative.c:2672 [inline] smp_text_poke_batch_finish+0xd36/0x1160 arch/x86/kernel/alternative.c:3061 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 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