INFO: task syz.3.630:8370 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.630 state:D stack:24960 pid:8370 tgid:8369 ppid:5822 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
sync_bdevs+0x27e/0x470 block/bdev.c:1304
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd76b19bf79
RSP: 002b:00007fd76c007028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd76b415fa0 RCX: 00007fd76b19bf79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd76b415fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd76b416038 R14: 00007fd76b415fa0 R15: 00007fff4d4393c8
Showing all locks held in the system:
1 lock held by ksoftirqd/0/15:
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:7/156:
#0: ffff88801c2ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90002fe7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fbbe130 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
#3: ffffffff8fbccf48 (rtnl_mutex){+.+.}-{4:4}, at: ipmr_net_exit_batch+0x20/0x90 net/ipv4/ipmr.c:3276
2 locks held by getty/5579:
#0: ffff8880332550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5998:
#0: ffff888026c71358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz.3.630/8370:
#0: ffff888026c71358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
1 lock held by syz.0.848/9257:
#0: ffff888026c71358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz-executor/9764:
1 lock held by syz.5.996/9860:
1 lock held by syz.5.996/9863:
#0: ffff8880533cd430 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x280/0xfd0 virt/kvm/kvm_main.c:4460
1 lock held by dhcpcd/9876:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9860 Comm: syz.5.996 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:vmx_vmexit+0x0/0xd0
Code: 0f 1f 84 00 00 00 00 00 f7 44 24 08 01 00 00 00 74 08 0f 01 c3 e9 cf 00 00 00 0f 01 c2 e9 c7 00 00 00 90 90 90 90 90 90 90 90 0f 1e fa 50 48 8b 44 24 08 8f 00 48 89 48 08 48 89 50 10 48 89
RSP: 0018:ffffc9000c9bf410 EFLAGS: 00000002
RAX: 0000000000000002 RBX: 0000000000000008 RCX: 0000040000000006
RDX: 000000000000ffff RSI: 00000000000004cb RDI: 0000000000000007
RBP: 0000000000001004 R08: 8000000000000004 R09: 000000000000c595
R10: 0000000000000000 R11: fffffffffffffffe R12: ffffffffffffffff
R13: 0000000000000100 R14: 00000000000000b1 R15: 000000000000008d
FS: 00007fd951dee6c0(0000) GS:ffff888125563000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007e396000 CR4: 00000000003526f0
Call Trace: