INFO: task syz.1.1350:11342 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1350 state:D stack:26696 pid:11342 ppid:5775 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
bdev_open_by_dev+0x77/0x100 block/bdev.c:859
setup_bdev_super+0x59/0x660 fs/super.c:1496
get_tree_bdev+0x346/0x520 fs/super.c:1588
vfs_get_tree+0x8c/0x280 fs/super.c:1764
do_new_mount+0x24b/0xa40 fs/namespace.c:3386
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff1b759ce59
RSP: 002b:00007ff1b84b2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff1b7816180 RCX: 00007ff1b759ce59
RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00002000000000c0
RBP: 00007ff1b7632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff1b7816218 R14: 00007ff1b7816180 R15: 00007ffc75e664e8
Showing all locks held in the system:
3 locks held by kworker/0:1/9:
1 lock held by khungtaskd/29:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:11/4868:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
#1: ffffc9000f887d00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000f887d00 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
2 locks held by getty/5527:
#0: ffff88802d14e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by udevd/5762:
#0: ffff888021e5d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/5764:
#0: ffff888021ff34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/5765:
#0: ffff888021fd44c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by udevd/5766:
#0: ffff888021e584c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
2 locks held by kworker/1:6/5813:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc9000475fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000475fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
1 lock held by syz.1.1350/11342:
#0: ffff888021e5d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by syz.3.1731/12628:
#0: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#0: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by vhost-12635/12637:
#0: ffff888045ba58e8 (&vtsk->exit_mutex){+.+.}-{3:3}, at: vhost_task_fn+0x373/0x460 kernel/vhost_task.c:54
#1: ffff88804cdf4978 (&worker->mutex){+.+.}-{3:3}, at: vhost_worker_killed+0x57/0x390 drivers/vhost/vhost.c:435
3 locks held by kvm-nx-lpage-re/12632:
#0: ffffffff8d15bb88 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline]
#0: ffffffff8d15bb88 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x26/0xe0 kernel/cgroup/cgroup-v1.c:61
#1: ffffffff8cfcd2b0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock+0x11/0x30 kernel/cgroup/cgroup.c:2414
#2: ffffffff8d15bd70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_task_all+0x30/0xe0 kernel/cgroup/cgroup-v1.c:62
1 lock held by dhcpcd/12642:
#0: ffff88806c822130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
#0: ffff88806c822130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3264
1 lock held by dhcpcd/12646:
#0: ffff888076a0e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
#0: ffff888076a0e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3264
1 lock held by dhcpcd/12649:
#0: ffff88805fed2130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
#0: ffff88805fed2130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3264
1 lock held by dhcpcd/12650:
#0: ffff88805e2d8130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
#0: ffff88805e2d8130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3264
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10446 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:list_empty include/linux/list.h:373 [inline]
RIP: 0010:list_splice_init include/linux/list.h:571 [inline]
RIP: 0010:ep_start_scan fs/eventpoll.c:632 [inline]
RIP: 0010:ep_send_events fs/eventpoll.c:1652 [inline]
RIP: 0010:ep_poll fs/eventpoll.c:1821 [inline]
RIP: 0010:do_epoll_wait+0x727/0x1b30 fs/eventpoll.c:2307
Code: ff 48 8b 7c 24 50 e8 a8 55 8d 08 48 8b 84 24 80 00 00 00 42 80 3c 28 00 48 8b 5c 24 18 74 08 48 89 df e8 8c 9c dc ff 4c 8b 3b <49> 39 df 0f 84 ae 00 00 00 e8 4b 65 84 ff 48 8b 9c 24 40 01 00 00
RSP: 0018:ffffc9000548fbe0 EFLAGS: 00000046
RAX: 1ffff1100ed30fa6 RBX: ffff888076987d30 RCX: 0000000000000001
RDX: ffff888076987d48 RSI: 0000000000000004 RDI: ffffc9000548fac0
RBP: ffffc9000548fe30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000a91f58 R12: ffffffff8202ca42
R13: dffffc0000000000 R14: ffff888076987d38 R15: ffff88802ec90618
FS: 00007f5983d7d880(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb94f3ea2f8 CR3: 000000002cdb4000 CR4: 00000000003526f0
Call Trace:
__do_sys_epoll_wait fs/eventpoll.c:2319 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2314 [inline]
__x64_sys_epoll_wait+0x1d8/0x230 fs/eventpoll.c:2314
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f59836a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc641af260 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 00007f5983d7d880 RCX: 00007f59836a7407
RDX: 0000000000000004 RSI: 00007ffc641af2f0 RDI: 0000000000000004
RBP: 000055afa87c9910 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000202 R12: 000055afa87dcad0
R13: 00007ffc641af2f0 R14: 0000000000000000 R15: 000055afa87dcad0