INFO: task syz.0.166:816 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.166 state:D stack:0 pid:816 tgid:815 ppid:290 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:6016 [inline]
__schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
__schedule_loop kernel/sched/core.c:7951 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7966
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
exit_aio+0x2ec/0x3c0 fs/aio.c:927
__mmput+0x30/0x340 kernel/fork.c:1356
mmput+0x55/0x170 kernel/fork.c:1383
exit_mm kernel/exit.c:574 [inline]
do_exit+0x909/0x2720 kernel/exit.c:941
do_group_exit+0x229/0x2f0 kernel/exit.c:1096
get_signal+0x1398/0x14e0 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ff87e99c819
RSP: 002b:00007ff87f7cf0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007ff87ec15fa8 RCX: 00007ff87e99c819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff87ec15fa8
RBP: 00007ff87ec15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff87ec16038 R14: 00007fff6342c600 R15: 00007fff6342c6e8
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 f9bdc9161095fb91188de70574256d407725efc9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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+0x2c6/0x370 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: 45 Comm: kworker/1:1 Not tainted syzkaller #0 f9bdc9161095fb91188de70574256d407725efc9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x86/0x90 kernel/kcov.c:316
Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 <5d> e9 14 03 1c 04 cc 0f 1f 00 b8 1c 38 5a 54 90 90 90 90 90 90 90
RSP: 0018:ffffc900002301e8 EFLAGS: 00000246
RAX: ffffffff84f960a8 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff888104a4b900 RSI: 00000000fffffffd RDI: 00000000fffffffd
RBP: ffffc900002301e8 R08: ffffc90000230540 R09: ffffc90000230550
R10: ffffc900002306b0 R11: fffff520000460da R12: 0000000000000001
R13: 1ffff110216fbf18 R14: 0000000000000003 R15: 00000000fffffffd
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f95f3e32328 CR3: 000000010c38e000 CR4: 00000000003526b0
Call Trace:
find_match+0x198/0x10e0 net/ipv6/route.c:790
__find_rr_leaf+0x24e/0x840 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+0x2ee/0x9e0 net/ipv6/route.c:2241
ip6_pol_route+0x17a/0x1360 net/ipv6/route.c:2277
ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2334
pol_lookup_func include/net/ip6_fib.h:626 [inline]
fib6_rule_lookup+0x4ee/0x6d0 net/ipv6/fib6_rules.c:117
ip6_route_input_lookup net/ipv6/route.c:2346 [inline]
ip6_route_input+0x62e/0x8f0 net/ipv6/route.c:2642
ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline]
ip6_rcv_finish+0x15a/0x3e0 net/ipv6/ip6_input.c:77
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:5776 [inline]
__netif_receive_skb net/core/dev.c:5889 [inline]
process_backlog+0x44b/0xad0 net/core/dev.c:6225
__napi_poll+0xd3/0x610 net/core/dev.c:6876
napi_poll net/core/dev.c:6945 [inline]
net_rx_action+0x5ea/0xd80 net/core/dev.c:7067
handle_softirqs+0x1ad/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
__raw_write_unlock_bh include/linux/rwlock_api_smp.h:281 [inline]
_raw_write_unlock_bh+0x33/0x70 kernel/locking/spinlock.c:366
neigh_periodic_work+0xa73/0xbc0 net/core/neighbour.c:1024
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c6/0x370 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: 130429 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:b6:04:c5:b7:1b:3e, 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:b6:04:c5:b7:1b:3e, 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 veth0_to_bridge with own address as source address (addr:b6:04:c5:b7:1b:3e, 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 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:1b, vlan:0)