INFO: task syz-executor.0:6067 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:6067 tgid:6067 ppid:6018 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: 0033:0x7f0566a7b8da RSP: 002b:00007fffeb825de0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f0566a7b8da RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f0566b9d980 R08: 0000001b2bd60000 R09: 3fffffffffffffff R10: 4000000000000000 R11: 0000000000000293 R12: 0000000000019cc2 R13: ffffffffffffffff R14: 00007f0566600000 R15: 0000000000019981 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5581: #0: ffff88814d17c0a0 (&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/6027: #0: ffff8881433dc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6067: #0: ffff8881433dc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 1 lock held by syz-executor.0/6236: #0: ffff8881433dc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6237: #0: ffff8881433dc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6268: #0: ffff8881433dc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6269: #0: ffff8881433dc358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 ============================================= 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline] RIP: 0010:do_raw_spin_unlock+0x3a/0x240 kernel/locking/spinlock_debug.c:141 Code: fb 49 bc 00 00 00 00 00 fc ff df 4c 8d 77 04 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 84 01 00 00 41 81 3e ad 4e ad de <0f> 85 f3 00 00 00 48 89 df be 04 00 00 00 e8 f3 c3 87 00 48 89 d8 RSP: 0018:ffffffff8dc07aa8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880b8827ac0 RCX: 66d0df5a28dcb400 RDX: 0000000000000000 RSI: ffffffff8d8f4661 RDI: ffff8880b8827ac0 RBP: ffffffff8dc07b60 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1b80f4c R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff8880b8827ac4 R15: 1ffffffff1b80f5c FS: 0000000000000000(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005611e68e6168 CR3: 000000000dd38000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x78/0x110 kernel/locking/spinlock.c:194 hrtimer_get_next_event+0x1a4/0x230 kernel/time/hrtimer.c:1528 cmp_next_hrtimer_event kernel/time/timer.c:1934 [inline] __get_next_timer_interrupt+0x7b1/0xa20 kernel/time/timer.c:2276 tick_nohz_next_event+0x1ba/0x3e0 kernel/time/tick-sched.c:922 tick_nohz_idle_stop_tick+0x144/0xc60 kernel/time/tick-sched.c:1218 cpuidle_idle_call kernel/sched/idle.c:188 [inline] do_idle+0x1e2/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147