INFO: task kworker/0:1H:4960 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H state:D stack:26776 pid:4960 tgid:4960 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: kblockd blk_mq_run_work_fn
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1107 [inline]
nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
nbd_queue_rq+0x889/0x1150 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2117
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_work_fn+0x16c/0x300 block/blk-mq.c:2532
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:12/3355:
4 locks held by kworker/0:1H/4960:
#0: ffff88801e2e4540 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801e2e4540 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000fd5fc40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000fd5fc40 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffff888025932818 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#2: ffff888025932818 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#2: ffff888025932818 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_work_fn+0x144/0x300 block/blk-mq.c:2531
#3: ffff888026b2e178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc1/0x1150 drivers/block/nbd.c:1199
4 locks held by klogd/4986:
#0: ffff8880b873b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
#1: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4346
#2: ffff88807fa28a90 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:572 [inline]
#2: ffff88807fa28a90 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x67/0x14d0 kernel/sched/core.c:4292
#3: ffff8880b873b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
2 locks held by getty/5387:
#0: ffff88803524f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:21/9049:
#0: ffff8880b873b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
#1: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: lock_hrtimer_base kernel/time/hrtimer.c:191 [inline]
#1: ffff8880b8724440 (psi_seq){-.-.}-{0:0}, at: hrtimer_start_range_ns+0x8c/0x3e0 kernel/time/hrtimer.c:1501
#2: ffff8880b8726058 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline]
#2: ffff8880b8726058 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1a9/0xed0 kernel/time/timer.c:1085
1 lock held by udevd/18753:
#0: ffff888026a1b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948
1 lock held by syz.5.4602/25491:
#0: ffff88802500c860 (&pipe->mutex){+.+.}-{4:4}, at: pipe_release+0x48/0x330 fs/pipe.c:827
1 lock held by syz.5.4602/25493:
#0: ffff88802500c860 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x3e/0x6b0 fs/splice.c:1287
2 locks held by syz.0.4606/25521:
#0: ffffffff9a9b3960 (nfnl_subsys_ipset){+.+.}-{4:4}, at: call_ad+0x266/0xb50 net/netfilter/ipset/ip_set_core.c:1747
#1: ffffffff8e95ff28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e95ff28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
=============================================
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 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 25521 Comm: syz.0.4606 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:lock_acquire+0xaf/0x350 kernel/locking/lockdep.c:5844
Code: 3d d5 e2 90 0e 00 0f 84 ce 00 00 00 65 8b 05 b8 c1 9d 11 85 c0 0f 85 bf 00 00 00 65 48 8b 05 c0 7c 9d 11 83 b8 9c 0b 00 00 00 <0f> 85 aa 00 00 00 4c 89 74 24 10 4d 89 fe 9c 41 5f fa 48 c7 c7 29
RSP: 0018:ffffc90003f4e4e0 EFLAGS: 00000246
RAX: ffff88801e379f00 RBX: 0000000000000000 RCX: 0000000000000201
RDX: 0000000000000000 RSI: ffffffff8176f23c RDI: 1ffffffff1d2b384
RBP: ffffffff8176f21f R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003f4e678 R11: ffffffff81b168f0 R12: 0000000000000002
R13: ffffffff8e959c20 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f89ab3f66c0(0000) GS:ffff888125326000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33a0bff8 CR3: 000000005b11e000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5362 [inline]
__kmalloc_noprof+0x375/0x720 mm/slub.c:5387
_kmalloc_noprof include/linux/slab.h:973 [inline]
_kzalloc_noprof include/linux/slab.h:1290 [inline]
hash_ipport4_resize+0x980/0x1970 net/netfilter/ipset/ip_set_hash_gen.h:710
call_ad+0x439/0xb50 net/netfilter/ipset/ip_set_core.c:1758
ip_set_ad+0x824/0x9d0 net/netfilter/ipset/ip_set_core.c:1842
nfnetlink_rcv_msg+0xcc2/0x12b0 net/netfilter/nfnetlink.c:300
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
nfnetlink_rcv+0x2b9/0x28c0 net/netfilter/nfnetlink.c:667
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f89ad19ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f89ab3f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f89ad416090 RCX: 00007f89ad19ce59
RDX: 0000000000000090 RSI: 00002000000002c0 RDI: 000000000000000c
RBP: 00007f89ad232e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f89ad416128 R14: 00007f89ad416090 R15: 00007ffee01ae2a8