INFO: task syz-executor.0:6179 blocked for more than 143 seconds. Not tainted 6.15.0-next-20250604-syzkaller-14339-g911483b25612 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27960 pid:6179 tgid:6178 ppid:6147 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 bdev_release+0x1a9/0x650 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:684 __fput+0x44c/0xa70 fs/file_table.c:467 task_work_run+0x1d1/0x260 kernel/task_work.c:227 get_signal+0x11ed/0x1340 kernel/signal.c:2807 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x4551e9 RSP: 002b:00007fd2bfc440d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 000000000054cf00 RCX: 00000000004551e9 RDX: ffffffffffffffff RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00000000004a06fd R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049f8fd R13: 000000000000000b R14: 000000000054cf00 R15: 00007ffd8a593428 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5593: #0: ffff88814ca3e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000361c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/6149: #0: ffff88814338e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz-executor.0/6179: #0: ffff88814338e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-next-20250604-syzkaller-14339-g911483b25612 #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:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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 6.15.0-next-20250604-syzkaller-14339-g911483b25612 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:seqcount_lockdep_reader_access+0xa/0x1c0 include/linux/seqlock.h:67 Code: 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 80 00 00 00 48 89 fb 65 RSP: 0018:ffffffff8de07c40 EFLAGS: 00000802 RAX: ffffffff81b231e5 RBX: 0000000000000000 RCX: ffffffff8de95280 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8de112c0 RBP: ffffffff8de07c48 R08: ffffffff8fa123f7 R09: 1ffffffff1f4247e R10: dffffc0000000000 R11: fffffbfff1f4247f R12: 1ffffffff1bc2258 R13: 1ffffffff1bc2240 R14: ffff8880b8628400 R15: ffff8880b86284c0 FS: 0000000000000000(0000) GS:ffff888125c4d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a728947660 CR3: 000000007edb0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: get_jiffies_update kernel/time/tick-sched.c:873 [inline] tick_nohz_next_event+0x47/0x3e0 kernel/time/tick-sched.c:897 tick_nohz_idle_stop_tick+0x144/0xc60 kernel/time/tick-sched.c:1218 cpuidle_idle_call kernel/sched/idle.c:183 [inline] do_idle+0x1e3/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:744 start_kernel+0x47d/0x500 init/main.c:1101 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147