INFO: task kworker/u8:64:20571 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:64 state:D stack:22936 pid:20571 tgid:20571 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: ib-unreg-wq ib_unregister_work
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
disable_device+0x1c6/0x320 drivers/infiniband/core/device.c:1325
__ib_unregister_device+0x2cb/0x3f0 drivers/infiniband/core/device.c:1555
ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1667
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:13/3556:
#0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88801aa9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000c197b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000c197b80 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
#3: ffffffff8df47440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816
2 locks held by getty/5591:
#0: ffff8880300fc0a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:8/5849:
#0: ffff888033040148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888033040148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000433fb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000433fb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff8880791d8ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
2 locks held by kworker/0:4/5911:
2 locks held by kworker/0:5/18274:
3 locks held by kworker/u8:64/20571:
#0: ffff8881436dc948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff8881436dc948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90011d37b80 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90011d37b80 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1551
2 locks held by syz.4.3812/21450:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.1.3814/21457:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.2.3823/21500:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.0.3872/21664:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.5.3869/21810:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.6.3926/21955:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by kworker/0:17/22065:
2 locks held by syz.8.3962/22144:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.7.3995/22320:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.3.4060/22610:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.3.4060/22613:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by kworker/0:23/22794:
2 locks held by syz.4.4116/22847:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.2.4132/22914:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
2 locks held by syz.9.4144/22970:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffff88806a2c0700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703
1 lock held by syz-executor/22998:
#0: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956
1 lock held by syz-executor/23130:
#0: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#0: ffffffff8df47578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956
1 lock held by syz.5.4198/23236:
#0: ffffffff8f304bf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
=============================================
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 10/25/2025
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]
__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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5911 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:__list_del_entry_valid_or_report+0x2a/0x190 lib/list_debug.c:49
Code: f3 0f 1e fa 41 57 41 56 41 55 41 54 53 48 89 fb 49 bd 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 05 e8 6f 28 8f fd 4c 8b 7b 08 48 89 d8 48 c1 e8 03 42 80 3c 28
RSP: 0018:ffffc90000006eb8 EFLAGS: 00000046
RAX: 1ffffd40003aa48b RBX: ffffea0001d52450 RCX: 5adc1cf604063500
RDX: 0000000000000001 RSI: ffffffff8d979277 RDI: ffffea0001d52458
RBP: ffffea0001d52440 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000db8 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffea0001d52450 R15: ffffea0000c18b90
FS: 0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
__list_del_entry_valid include/linux/list.h:132 [inline]
__list_del_entry include/linux/list.h:223 [inline]
list_del include/linux/list.h:237 [inline]
remove_partial mm/slub.c:3389 [inline]
get_partial_node+0x14b/0x460 mm/slub.c:3532
get_partial mm/slub.c:3630 [inline]
___slab_alloc+0xe7f/0x1960 mm/slub.c:4631
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
kmem_cache_alloc_node_noprof+0x4ce/0x720 mm/slub.c:5315
__alloc_skb+0x255/0x430 net/core/skbuff.c:679
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack+0x16c/0xe20 net/netfilter/nf_synproxy_core.c:460
nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6137 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6250
process_backlog+0x622/0x1500 net/core/dev.c:6602
__napi_poll+0xae/0x320 net/core/dev.c:7666
napi_poll net/core/dev.c:7729 [inline]
net_rx_action+0x672/0xe50 net/core/dev.c:7881
handle_softirqs+0x27d/0x850 kernel/softirq.c:622
do_softirq+0xec/0x180 kernel/softirq.c:523
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
neigh_periodic_work+0xc28/0xe50 net/core/neighbour.c:1039
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246