INFO: task syz-executor128:5094 blocked for more than 143 seconds. Not tainted 6.9.0-next-20240514-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor128 state:D stack:26040 pid:5094 tgid:5093 ppid:5090 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 bdev_release+0x184/0x700 block/bdev.c:1080 blkdev_release+0x15/0x20 block/fops.c:623 __fput+0x406/0x8b0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 ptrace_notify+0x2d2/0x380 kernel/signal.c:2402 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] syscall_exit_work+0xc6/0x190 kernel/entry/common.c:173 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x273/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6e40084479 RSP: 002b:00007f6e4003c228 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f6e4010b328 RCX: 00007f6e40084479 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f6e4010b320 R08: 00007f6e4003c6c0 R09: 00007f6e4003c6c0 R10: 00007f6e4003c6c0 R11: 0000000000000246 R12: 00007f6e4010b32c R13: 00007f6e400d818c R14: 64626e2f7665642f R15: 00007ffd7e135ba8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4841: #0: ffff88802aabb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by udevd/5091: #0: ffff8880206c64c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xe5/0xc70 block/bdev.c:897 1 lock held by syz-executor128/5094: #0: ffff8880206c64c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x184/0x700 block/bdev.c:1080 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.9.0-next-20240514-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112