INFO: task syz.3.53:509 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.53 state:D stack:0 pid:509 tgid:509 ppid:297 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6063 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7883
__schedule_loop kernel/sched/core.c:7960 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7975
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+0x368/0x650 kernel/sched/completion.c:127
wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
rcu_barrier+0x45a/0x580 kernel/rcu/tree.c:4657
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
tun_detach drivers/net/tun.c:704 [inline]
tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520
__fput+0x208/0xa30 fs/file_table.c:447
____fput+0x20/0x30 fs/file_table.c:475
task_work_run+0x1e5/0x260 kernel/task_work.c:246
resume_user_mode_work+0x35/0x50 include/linux/resume_user_mode.h:50
exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x63/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f37a479e159
RSP: 002b:00007ffce136dbb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffce136dca0 RCX: 00007f37a479e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000000a8bd R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2e520000 R11: 0000000000000246 R12: 00007ffce136dce0
R13: 00007f37a4a25fac R14: 000000000000a8fe R15: 00007f37a4a25fa0
INFO: task syz.0.54:518 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.54 state:D stack:0 pid:518 tgid:516 ppid:294 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:6063 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7883
__schedule_loop kernel/sched/core.c:7960 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7975
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8032
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x902/0x1b90 kernel/locking/mutex.c:806
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rcu_barrier+0x4d/0x580 kernel/rcu/tree.c:4589
netdev_run_todo+0x118/0xce0 net/core/dev.c:10912
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
tun_detach drivers/net/tun.c:704 [inline]
tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520
__fput+0x208/0xa30 fs/file_table.c:447
____fput+0x20/0x30 fs/file_table.c:475
task_work_run+0x1e5/0x260 kernel/task_work.c:246
get_signal+0x12b3/0x1490 kernel/signal.c:2706
arch_do_signal_or_restart+0xbc/0x700 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: 0033:0x7fd03f19e159
RSP: 002b:00007fd0400de028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fd03f426090 RCX: 00007fd03f19e159
RDX: 00002000000000c0 RSI: 00000000400454ca RDI: 0000000000000005
RBP: 00007fd03f23503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd03f426128 R14: 00007fd03f426090 R15: 00007ffdb1fe2798
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 854a78f96d1de0e57c2b3161b903feab84b64500
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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+0xe45/0xf90 kernel/hung_task.c:423
kthread+0x2c4/0x360 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 335 Comm: kworker/1:4 Not tainted syzkaller #0 854a78f96d1de0e57c2b3161b903feab84b64500
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x14/0x90 kernel/kcov.c:314
Code: 1f 04 cc 0f 1f 00 b8 33 03 06 0a 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 15 0c 70 7d 7e <65> 8b 0d 0d 70 7d 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75
RSP: 0018:ffffc9000022ff68 EFLAGS: 00000246
RAX: ffffffff84fb12c9 RBX: 0000000000000000 RCX: 0000000000000100
RDX: ffff888107ffdf00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000022ff68 R08: ffffc90000230340 R09: ffffc90000230350
R10: ffffc900002304b0 R11: fffff5200004609a R12: 000000000000000a
R13: ffff88812fbec8c0 R14: 0000000000000003 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd3cad1ff0 CR3: 000000010b774000 CR4: 00000000003526b0
Call Trace:
rt6_score_route+0xb9/0x880 net/ipv6/route.c:-1
find_match+0x176/0x10d0 net/ipv6/route.c:786
__find_rr_leaf+0x249/0x840 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+0x2d0/0x980 net/ipv6/route.c:2242
ip6_pol_route+0x17a/0x1370 net/ipv6/route.c:2278
ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2335
pol_lookup_func include/net/ip6_fib.h:647 [inline]
__fib6_rule_action net/ipv6/fib6_rules.c:234 [inline]
fib6_rule_action+0x9e7/0xbe0 net/ipv6/fib6_rules.c:272
fib_rules_lookup+0x48e/0xa20 net/core/fib_rules.c:321
fib6_rule_lookup+0x191/0x6d0 net/ipv6/fib6_rules.c:109
ip6_route_input_lookup net/ipv6/route.c:2347 [inline]
ip6_route_input+0x60d/0x8d0 net/ipv6/route.c:2643
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+0xf1/0x240 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core net/core/dev.c:5801 [inline]
__netif_receive_skb net/core/dev.c:5914 [inline]
process_backlog+0x472/0xaf0 net/core/dev.c:6250
__napi_poll+0xcd/0x600 net/core/dev.c:6901
napi_poll net/core/dev.c:6970 [inline]
net_rx_action+0x5dc/0xd70 net/core/dev.c:7092
handle_softirqs+0x1aa/0x620 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+0xa6a/0xbb0 net/core/neighbour.c:1024
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f4/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c4/0x360 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: 98569 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 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 veth0_to_bridge with own address as source address (addr:12:8b:07:b2:31:ab, 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)
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:12:8b:07:b2:31:ab, 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)