INFO: task syz-executor.0:6048 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:25608 pid:6048 tgid:6048 ppid:6022 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_release+0x1a9/0x650 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:709 __fput+0x44c/0xa70 fs/file_table.c:468 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0ddb67890a RSP: 002b:00007ffd545185e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f0ddb67890a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f0ddb78d960 R08: 0000001b2c160000 R09: 3fffffffffffffff R10: 4000000000000000 R11: 0000000000000293 R12: 000000000001ba13 R13: 00007f0ddb78bf6c R14: 000000000001b706 R15: 00007f0ddbb90000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5579: #0: ffff88814ce6e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/6023: #0: ffff888141fb5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6048: #0: ffff888141fb5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 ============================================= 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 10/02/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 3526 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:227 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3820 [inline] RIP: 0010:validate_chain+0x46/0x2140 kernel/locking/lockdep.c:3876 Code: 48 89 84 24 d8 00 00 00 8b 46 20 89 c1 81 e1 00 80 04 00 81 f9 00 00 04 00 0f 85 61 02 00 00 41 89 d4 49 89 f6 25 ff 1f 00 00 <48> 0f a3 05 e2 9a fb 11 48 89 3c 24 72 36 83 3d 55 2a ff 17 00 75 RSP: 0018:ffffc9000c3873d0 EFLAGS: 00000002 RAX: 0000000000000038 RBX: 0000000000000006 RCX: 0000000000040000 RDX: 0000000000000000 RSI: ffff8880305b8c20 RDI: ffff8880305b8000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff82116c1e R10: dffffc0000000000 R11: fffff94000010ce1 R12: 0000000000000000 R13: ffff8880305b8b30 R14: ffff8880305b8c20 R15: 58f140a5e4b05284 FS: 0000000000000000(0000) GS:ffff888125d0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055712d3f0168 CR3: 000000000df38000 CR4: 0000000000350ef0 Call Trace: __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:401 get_locked_pte include/linux/mm.h:2815 [inline] __text_poke+0x2e6/0xa10 arch/x86/kernel/alternative.c:2467 text_poke arch/x86/kernel/alternative.c:2552 [inline] smp_text_poke_batch_finish+0xd0f/0x1130 arch/x86/kernel/alternative.c:2941 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:857 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245