INFO: task poweroff:12283 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:poweroff state:D stack:23704 pid:12283 tgid:12283 ppid:5217 task_flags:0x400000 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 sync_bdevs+0x1ac/0x340 block/bdev.c:1288 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff9fbad6f37 RSP: 002b:00007ffe9c897e98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007ff9fbad6f37 RDX: ffffffffffffff88 RSI: 00007ff9fbc6fe51 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe9c897ff8 R14: 00007ff9fbcb9000 R15: 000055a0b7959d98 INFO: task syz.6.1540:12345 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1540 state:D stack:27240 pid:12345 tgid:12344 ppid:7494 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bdev_open+0xe0/0xd30 block/bdev.c:945 bdev_file_open_by_dev+0x1be/0x240 block/bdev.c:1059 setup_bdev_super+0x5a/0x5b0 fs/super.c:1609 get_tree_bdev_flags+0x366/0x4d0 fs/super.c:1689 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1274 [inline] do_new_mount_fc fs/namespace.c:3726 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3802 do_mount fs/namespace.c:4125 [inline] __do_sys_mount fs/namespace.c:4324 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4301 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbaed78eba9 RSP: 002b:00007fbaee611038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fbaed9d5fa0 RCX: 00007fbaed78eba9 RDX: 0000200000000140 RSI: 0000200000000100 RDI: 0000200000000000 RBP: 00007fbaed811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000208083 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbaed9d6038 R14: 00007fbaed9d5fa0 R15: 00007ffc510d0528 Showing all locks held in the system: 2 locks held by ksoftirqd/1/23: #0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 #1: ffff8880b8724008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 1 lock held by khungtaskd/31: #0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5624: #0: ffff88814d85a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by kworker/u8:12/6024: 1 lock held by udevd/9585: #0: ffff8881423f9358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 5 locks held by kworker/0:14/11555: #0: ffff888021a88548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888021a88548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9001b5cfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9001b5cfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88802834f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff88802834f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff888063dc5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff888063dc5198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff88823be1ce78 (&(&priv->bus_notifier)->rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379 1 lock held by poweroff/12283: #0: ffff8881423f9358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288 2 locks held by syz.6.1540/12345: #0: ffff888055c420e0 (&type->s_umount_key#102/1){+.+.}-{4:4}, at: alloc_super+0x1bb/0x930 fs/super.c:344 #1: ffff8881423f9358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 1 lock held by syz.3.1991/14163: #0: ffff888141bea420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160 1 lock held by syz.7.2050/14524: 3 locks held by rm/14592: ============================================= 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 08/18/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 1145 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:set_irq_regs include/asm-generic/irq_regs.h:29 [inline] RIP: 0010:__sysvec_apic_timer_interrupt+0x16b/0x410 arch/x86/kernel/apic/apic.c:1061 Code: e8 1a 4c 35 00 84 c0 75 0d 80 3d 1f cc 5d 0e 00 0f 84 f9 00 00 00 48 c7 c7 00 af a7 8b e8 2d 42 1a 0a 65 48 8b 05 2d c1 77 11 <48> c7 c7 20 af a7 8b e8 19 42 1a 0a 65 4c 89 3d 19 c1 77 11 5b 41 RSP: 0018:ffffc90000007fd0 EFLAGS: 00000082 RAX: ffffc90003caf718 RBX: 0000000000000000 RCX: 4fe71f1328f88300 RDX: 0000000000000000 RSI: ffffffff8ba7af00 RDI: ffffffff8c050400 RBP: 0000000000000000 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746 R10: dffffc0000000000 R11: fffffbfff1fca747 R12: dffffc0000000000 R13: 0000000000000000 R14: 1ffff110170c4720 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881257a7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6ab0e57e8 CR3: 00000000779b2000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 0000000000000047 DR2: 0000000000000005 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 0b e3 49 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003caf7c0 EFLAGS: 00000206 RAX: 4fe71f1328f88300 RBX: 0000000000000000 RCX: 4fe71f1328f88300 RDX: 0000000000000000 RSI: ffffffff8de9418e RDI: ffffffff8c050400 RBP: ffffffff8b541120 R08: 0000000000000000 R09: ffffffff8b541120 R10: dffffc0000000000 R11: ffffed100ccb1617 R12: 0000000000000002 R13: ffffffff8e53c820 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:762 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:834 [inline] batadv_iv_ogm_schedule+0x454/0xf00 net/batman-adv/bat_iv_ogm.c:874 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1714 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245