INFO: task kworker/u8:0:12 blocked for more than 126 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:0 pid:12 tgid:12 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5996 [inline]
__schedule+0x134f/0x1ea0 kernel/sched/core.c:7843
__schedule_loop kernel/sched/core.c:7924 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7939
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589
cleanup_net+0x908/0xc90 net/core/net_namespace.c:653
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
INFO: task kworker/1:5:548 blocked for more than 126 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:5 state:D stack:0 pid:548 tgid:548 ppid:2 flags:0x00004000
Workqueue: events fqdir_free_fn
Call Trace:
context_switch kernel/sched/core.c:5996 [inline]
__schedule+0x134f/0x1ea0 kernel/sched/core.c:7843
__schedule_loop kernel/sched/core.c:7924 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7939
schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x369/0x650 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657
fqdir_free_fn+0x36/0x150 net/ipv4/inet_fragment.c:167
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 e74179280c147a83e3a201a5967fe5af4e04851c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
watchdog+0xdad/0xf00 kernel/hung_task.c:423
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 e74179280c147a83e3a201a5967fe5af4e04851c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
RIP: 0010:do_raw_spin_trylock include/linux/spinlock.h:193 [inline]
RIP: 0010:__raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
RIP: 0010:_raw_spin_trylock+0x92/0x140 kernel/locking/spinlock.c:138
Code: 43 c6 44 3c 04 04 be 04 00 00 00 e8 98 df 3e fc 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 91 00 00 00 8b 03 89 44 24 20 <85> c0 75 78 4c 8d 74 24 20 48 89 df be 04 00 00 00 e8 98 df 3e fc
RSP: 0018:ffffc9000022f860 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8881f6f50d00 RCX: ffffffff85a099e8
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8881f6f50d00
RBP: ffffc9000022f8f0 R08: ffff8881f6f50d03 R09: 1ffff1103edea1a0
R10: dffffc0000000000 R11: ffffed103edea1a1 R12: 1ffff92000045f0c
R13: dffffc0000000000 R14: 1ffff1103edea17d R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fadfe016038 CR3: 000000010cba2000 CR4: 00000000003526b0
Call Trace:
rcu_nocb_bypass_lock kernel/rcu/tree_nocb.h:96 [inline]
rcu_nocb_flush_bypass kernel/rcu/tree_nocb.h:358 [inline]
rcu_nocb_try_bypass kernel/rcu/tree_nocb.h:446 [inline]
call_rcu_nocb+0x3ff/0xc80 kernel/rcu/tree_nocb.h:606
__call_rcu_common+0x43b/0x720 kernel/rcu/tree.c:3117
call_rcu_hurry+0xf/0x30 kernel/rcu/tree.c:3149
dst_release+0x1a3/0x240 net/core/dst.c:177
refdst_drop include/net/dst.h:263 [inline]
skb_dst_drop include/net/dst.h:275 [inline]
__dev_queue_xmit+0x8a3/0x3690 net/core/dev.c:4475
dev_queue_xmit include/linux/netdevice.h:3141 [inline]
neigh_hh_output include/net/neighbour.h:535 [inline]
neigh_output include/net/neighbour.h:549 [inline]
ip6_finish_output2+0x1175/0x19c0 net/ipv6/ip6_output.c:141
__ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
ip6_finish_output+0x54e/0xb40 net/ipv6/ip6_output.c:226
NF_HOOK_COND include/linux/netfilter.h:306 [inline]
ip6_output+0x1fe/0x420 net/ipv6/ip6_output.c:247
dst_output include/net/dst.h:459 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
ndisc_send_skb+0x7ed/0xd60 net/ipv6/ndisc.c:513
ndisc_send_na+0x8bf/0xb40 net/ipv6/ndisc.c:578
ndisc_recv_ns+0x8fe/0x1300 net/ipv6/ndisc.c:962
ndisc_rcv+0x41a/0x650 net/ipv6/ndisc.c:1864
icmpv6_rcv+0xee1/0x1790 net/ipv6/icmp.c:991
ip6_protocol_deliver_rcu+0xbc5/0x12f0 net/ipv6/ip6_input.c:436
ip6_input_finish net/ipv6/ip6_input.c:481 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
ip6_input+0x1cd/0x3a0 net/ipv6/ip6_input.c:490
ip6_mc_input+0x35a/0x6c0 net/ipv6/ip6_input.c:584
dst_input include/net/dst.h:469 [inline]
ip6_rcv_finish+0x360/0x3e0 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:317 [inline]
ipv6_rcv+0xf1/0x240 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5763 [inline]
__netif_receive_skb net/core/dev.c:5876 [inline]
process_backlog+0x44b/0xad0 net/core/dev.c:6212
__napi_poll+0xd0/0x610 net/core/dev.c:6863
napi_poll net/core/dev.c:6932 [inline]
net_rx_action+0x5ea/0xd80 net/core/dev.c:7054
handle_softirqs+0x1aa/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xb8/0x110 kernel/softirq.c:503
__local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_do_batch+0x5d9/0xd40 kernel/rcu/tree.c:2594
nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
rcu_nocb_cb_kthread+0x524/0xb30 kernel/rcu/tree_nocb.h:957
kthread+0x2c9/0x370 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
net_ratelimit: 76052 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:1e:aa:b2:cd:35:99, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:1e:aa:b2:cd:35:99, vlan:0)
net_ratelimit: 102088 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:1e:aa:b2:cd:35:99, vlan:0)