INFO: task syz-executor.0:6195 blocked for more than 143 seconds. Not tainted 6.15.0-rc7-syzkaller-g94305e83eccb #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27288 pid:6195 tgid:6194 ppid:6139 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 bdev_release+0x1a9/0x650 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:660 __fput+0x449/0xa70 fs/file_table.c:465 task_work_run+0x1d4/0x260 kernel/task_work.c:227 get_signal+0x11c5/0x1310 kernel/signal.c:2807 arch_do_signal_or_restart+0x95/0x780 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+0x8b/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f705b67c899 RSP: 002b:00007f705c3980c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f705b79bf80 RCX: 00007f705b67c899 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f705b6d8ad0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f705b79bf80 R15: 00007ffd552433c8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5583: #0: ffff88803093c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/6141: #0: ffff8881437fd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6195: #0: ffff8881437fd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 1 lock held by syz-executor.0/6515: #0: ffff8881437fd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6538: #0: ffff8881437fd358 (&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 6.15.0-rc7-syzkaller-g94305e83eccb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc7-syzkaller-g94305e83eccb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: 0x0 (bat_events) RIP: 0010:wq_node_nr_active kernel/workqueue.c:1555 [inline] RIP: 0010:pwq_dec_nr_active kernel/workqueue.c:1933 [inline] RIP: 0010:pwq_dec_nr_in_flight+0x90/0xdd0 kernel/workqueue.c:1994 Code: d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 66 8f 93 00 4c 8b 33 49 8d 9e c0 01 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 ec 0b 00 00 8b 1b 89 de 83 e6 02 31 ff e8 fa bd 33 00 RSP: 0018:ffffc90000127a80 EFLAGS: 00000802 RAX: 0000000000000000 RBX: ffff8880309649c0 RCX: ffff88801c6c0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88802fef5800 R08: ffff88801c289b27 R09: 0000000000000000 R10: ffff88801c289b10 R11: ffffed1003851365 R12: dffffc0000000000 R13: ffff88801a0a0000 R14: ffff888030964800 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561bced3d660 CR3: 0000000030f22000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work kernel/workqueue.c:3293 [inline] process_scheduled_works+0x100b/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245