INFO: task syz-executor.0:6061 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28264 pid:6061 tgid:6060 ppid:6004 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 bdev_release+0x15a/0x6d0 block/bdev.c:1128 blkdev_release+0x15/0x20 block/fops.c:702 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 get_signal+0x1d0/0x26d0 kernel/signal.c:2807 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6b6b87c859 RSP: 002b:00007f6b6abf60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f6b6b99bf80 RCX: 00007f6b6b87c859 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f6b6b8d8ad0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f6b6b99bf80 R15: 00007ffeae13f088 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:2/34: 2 locks held by getty/5572: #0: ffff8880360850a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by udevd/5996: #0: ffff88802631a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz-executor.0/6061: #0: ffff88802631a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x15a/0x6d0 block/bdev.c:1128 1 lock held by syz-executor.0/6222: #0: ffff88802631a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz-executor.0/6250: #0: ffff88802631a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x672/0x7d0 arch/x86/kernel/process.c:158 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 syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:update_rq_clock+0x0/0xc70 kernel/sched/core.c:832 Code: 20 e8 44 18 9b 00 48 8b 54 24 20 e9 cc fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 41 55 41 54 RSP: 0018:ffffc90000007b18 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000008126 RCX: ffffffff81607a9e RDX: ffffffff8e097a00 RSI: ffffffff8dadcbf4 RDI: ffff8880b853a380 RBP: ffffc90000007cf8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff93a5b380 R13: 0000000000000200 R14: ffff8880b853a380 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881249df000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e9efc47168 CR3: 000000000e182000 CR4: 00000000003526f0 Call Trace: sched_balance_rq+0xbd9/0x3110 kernel/sched/fair.c:11794 sched_balance_domains+0x6ff/0xee0 kernel/sched/fair.c:12227 _nohz_idle_balance.isra.0+0x5fc/0x840 kernel/sched/fair.c:12662 handle_softirqs+0x216/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0xa4/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: e7 75 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 f6 24 00 fb f4 0c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c2 RAX: 000000000014955b RBX: 0000000000000000 RCX: ffffffff8b6522d9 RDX: 0000000000000000 RSI: ffffffff8db0273a RDI: ffffffff8bf1cfc0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff908324d0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f3/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148