INFO: task syz.2.402:7907 blocked for more than 143 seconds. Not tainted 6.14.0-rc2-syzkaller-00056-gab68d7eb7b1a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.402 state:D stack:25232 pid:7907 tgid:7907 ppid:5819 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 bdev_release+0x15a/0x6d0 block/bdev.c:1086 blkdev_release+0x15/0x20 block/fops.c:660 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd76e58cde9 RSP: 002b:00007ffc51504b68 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fd76e7a7ba0 RCX: 00007fd76e58cde9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fd76e7a7ba0 R08: 0000000000000210 R09: 0000001e51504e5f R10: 00007fd76e7a7ac0 R11: 0000000000000246 R12: 000000000002c038 R13: 00007fd76e7a6080 R14: ffffffffffffffff R15: 00007ffc51504c80 INFO: task syz.2.402:7909 blocked for more than 144 seconds. Not tainted 6.14.0-rc2-syzkaller-00056-gab68d7eb7b1a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.402 state:D stack:26976 pid:7909 tgid:7907 ppid:5819 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 bdev_release+0x15a/0x6d0 block/bdev.c:1086 blkdev_release+0x15/0x20 block/fops.c:660 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd76e58cde9 RSP: 002b:00007fd76f48b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fd76e7a5fa0 RCX: 00007fd76e58cde9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 000000000000000a RBP: 00007fd76e60e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd76e7a5fa0 R15: 00007ffc51504a08 Showing all locks held in the system: 1 lock held by ksoftirqd/1/24: 1 lock held by khungtaskd/30: #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 2 locks held by getty/5580: #0: ffff88814cdfa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 1 lock held by udevd/6082: #0: ffff88802617b4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe20 block/bdev.c:903 1 lock held by syz.2.402/7907: #0: ffff88802617b4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1086 1 lock held by syz.2.402/7909: #0: ffff88802617b4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1086 3 locks held by kworker/u8:27/8747: #0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline] #0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591 #1: ffff8880b8728a88 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 #2: ffff8880b872a518 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x12f/0x1e0 kernel/time/timer.c:1046 1 lock held by syz.1.762/9335: #0: ffff88802617b4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1246 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc2-syzkaller-00056-gab68d7eb7b1a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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+0x1a/0x20 drivers/acpi/processor_idle.c:111