INFO: task kworker/u8:16:4208 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:16 state:D stack:0 pid:4208 tgid:4208 ppid:2 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5945 [inline]
__schedule+0x1322/0x1df0 kernel/sched/core.c:7791
__schedule_loop kernel/sched/core.c:7872 [inline]
schedule+0xc6/0x240 kernel/sched/core.c:7887
schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common+0x359/0x630 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4657
netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10868
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
default_device_exit_batch+0x815/0x8a0 net/core/dev.c:12035
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x731/0xc70 net/core/net_namespace.c:642
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319
worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
kthread+0x2c7/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0dd0103ec329b4c3ce546fdd10bdf8515cdb9785
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:94
dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
dump_stack+0x19/0x20 lib/dump_stack.c:129
nmi_cpu_backtrace+0x2bf/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+0xd8f/0xed0 kernel/hung_task.c:423
kthread+0x2c7/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 0dd0103ec329b4c3ce546fdd10bdf8515cdb9785
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x5/0x70 kernel/kcov.c:210
Code: e8 f0 20 52 00 5b 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc b8 b7 35 84 f1 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 48 8b 45 08 65 48 8b 0c 25 00 eb 04 00 65 8b 15 2c 08 7f
RSP: 0018:ffffc900000071e8 EFLAGS: 00000246
RAX: ffffffff84e71948 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff888103660000 RSI: 00000000fffffffd RDI: 00000000fffffffd
RBP: ffffc900000072b0 R08: ffffc90000007540 R09: ffffc90000007550
R10: ffffc900000076b0 R11: fffff52000000eda R12: 0000000000000001
R13: 1ffff11023d5ad98 R14: 0000000000000003 R15: 00000000fffffffd
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbbb67c5f40 CR3: 0000000138fcc000 CR4: 00000000003526b0
Call Trace:
__find_rr_leaf+0x23c/0x790 net/ipv6/route.c:869
find_rr_leaf net/ipv6/route.c:890 [inline]
rt6_select net/ipv6/route.c:934 [inline]
fib6_table_lookup+0x2c5/0x9b0 net/ipv6/route.c:2230
ip6_pol_route+0x167/0x12c0 net/ipv6/route.c:2266
ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2323
pol_lookup_func include/net/ip6_fib.h:626 [inline]
fib6_rule_lookup+0x4cc/0x6b0 net/ipv6/fib6_rules.c:117
ip6_route_input_lookup net/ipv6/route.c:2335 [inline]
ip6_route_input+0x59f/0x8d0 net/ipv6/route.c:2631
ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline]
ip6_rcv_finish+0x15a/0x3c0 net/ipv6/ip6_input.c:77
NF_HOOK include/linux/netfilter.h:317 [inline]
ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5757 [inline]
__netif_receive_skb net/core/dev.c:5870 [inline]
process_backlog+0x44b/0xae0 net/core/dev.c:6206
__napi_poll+0xd0/0x610 net/core/dev.c:6857
napi_poll net/core/dev.c:6926 [inline]
net_rx_action+0x584/0xce0 net/core/dev.c:7048
handle_softirqs+0x1ab/0x630 kernel/softirq.c:621
__do_softirq+0xf/0x16 kernel/softirq.c:659
do_softirq+0xa6/0x100 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+0x5c6/0xd20 kernel/rcu/tree.c:2594
nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
kthread+0x2c7/0x370 kernel/kthread.c:389
ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
net_ratelimit: 148890 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)