INFO: task udevd:11132 blocked for more than 143 seconds. Not tainted 6.14.0-rc3-next-20250218-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:21584 pid:11132 tgid:11132 ppid:5201 task_flags:0x40054c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5373 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6760 __schedule_loop kernel/sched/core.c:6837 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6852 io_schedule+0x8d/0x110 kernel/sched/core.c:7687 folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1319 __folio_lock mm/filemap.c:1666 [inline] folio_lock include/linux/pagemap.h:1163 [inline] __filemap_get_folio+0x14e/0xae0 mm/filemap.c:1919 truncate_inode_pages_range+0x588/0x10e0 mm/truncate.c:364 kill_bdev block/bdev.c:91 [inline] blkdev_flush_mapping+0x108/0x270 block/bdev.c:670 blkdev_put_whole block/bdev.c:677 [inline] bdev_release+0x460/0x700 block/bdev.c:1102 blkdev_release+0x15/0x20 block/fops.c:660 __fput+0x3e9/0x9f0 fs/file_table.c:464 task_work_run+0x24f/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:952 do_group_exit+0x207/0x2c0 kernel/exit.c:1101 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7ff7916b6a RSP: 002b:00007ffc8656b678 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffffc RBX: 0000000000000000 RCX: 00007f7ff7916b6a RDX: 0000000000000400 RSI: 00005634c1835388 RDI: 0000000000000009 RBP: 0000000000000400 R08: 00005634c1835360 R09: 0000000000000008 R10: 0000000000000051 R11: 0000000000000246 R12: 00005634c1835360 R13: 00005634c1835378 R14: 00005634c182bb08 R15: 00005634c182bab0 Showing all locks held in the system: 6 locks held by kworker/u8:0/11: 1 lock held by khungtaskd/30: #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 3 locks held by kworker/1:1/51: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000bbfc60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bbfc60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:998 2 locks held by getty/5585: #0: ffff8880355da0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fce2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5826: 1 lock held by udevd/11132: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x17e/0x700 block/bdev.c:1086 1 lock held by syz.3.2312/14042: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 1 lock held by syz.3.2312/14049: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 1 lock held by syz.3.2312/14051: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 1 lock held by syz.3.2312/14054: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 1 lock held by syz.3.2312/14058: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 1 lock held by syz.3.2312/14061: #0: ffff8881437ce4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246 2 locks held by syz.5.2510/14944: 1 lock held by syz.4.2512/14940: #0: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-next-20250218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111