INFO: task syz-executor:8479 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:0 pid:8479 tgid:8479 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6026 [inline]
__schedule+0x14ce/0x2100 kernel/sched/core.c:7893
__schedule_loop kernel/sched/core.c:7974 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7989
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rtnl_lock net/core/rtnetlink.c:79 [inline]
rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6675
netlink_rcv_skb+0x259/0x4f0 net/netlink/af_netlink.c:2545
rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x68d/0x700 net/socket.c:2216
__do_sys_sendto net/socket.c:2228 [inline]
__se_sys_sendto net/socket.c:2224 [inline]
__x64_sys_sendto+0xe9/0x100 net/socket.c:2224
x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:47 [inline]
do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fef20f57fd7
RSP: 002b:00007ffd6be6bb10 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555559378500 RCX: 00007fef20f57fd7
RDX: 0000000000000028 RSI: 00007fef21d44670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd6be6bb74 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fef21d44670 R15: 0000000000000000
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 29c6904b08c3b1e8518f4116e2e8016f6159917e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+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: 785 Comm: kworker/u8:66 Not tainted syzkaller #0 29c6904b08c3b1e8518f4116e2e8016f6159917e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
RIP: 0010:skb_network_header include/linux/skbuff.h:3067 [inline]
RIP: 0010:ipv6_hdr include/linux/ipv6.h:116 [inline]
RIP: 0010:ip6_multipath_l3_keys+0xe9/0x6d0 net/ipv6/route.c:2355
Code: 00 00 4d 8b b4 24 e0 00 00 00 4c 89 64 24 30 49 81 c4 b8 00 00 00 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 1e 04 00 00 <45> 0f b7 24 24 42 c7 44 2b 04 00 00 00 00 42 c6 44 2b 08 00 ba 28
RSP: 0018:ffffc9000022fda0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff92000045fc0 RCX: ffff888104310000
RDX: 0000000000000100 RSI: ffffc90000230190 RDI: ffffc9000022fe20
RBP: ffffc9000022fef0 R08: ffffc900002301df R09: 0000000000000000
R10: ffffc90000230190 R11: fffff5200004603c R12: ffff88817f79a838
R13: dffffc0000000000 R14: ffff888153760a80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4eed45000 CR3: 000000010bfca000 CR4: 00000000003526b0
Call Trace:
rt6_multipath_hash+0x3fb/0x15b0 net/ipv6/route.c:2527
ip6_route_input+0x75a/0x8f0 net/ipv6/route.c:2641
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]
netif_receive_skb_internal net/core/dev.c:6000 [inline]
netif_receive_skb+0x147/0x7b0 net/core/dev.c:6059
br_netif_receive_skb net/bridge/br_input.c:30 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70
br_handle_frame_finish+0x120c/0x17a0 net/bridge/br_input.c:221
nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
__netif_receive_skb_core+0xfae/0x3ab0 net/core/dev.c:5695
__netif_receive_skb_one_core net/core/dev.c:5799 [inline]
__netif_receive_skb net/core/dev.c:5914 [inline]
process_backlog+0x3e5/0xad0 net/core/dev.c:6250
__napi_poll+0xd3/0x610 net/core/dev.c:6901
napi_poll net/core/dev.c:6970 [inline]
net_rx_action+0x5ea/0xd80 net/core/dev.c:7092
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
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
addrconf_ifdown+0x614/0x1980 net/ipv6/addrconf.c:3950
addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1
notifier_call_chain+0x10e/0x2b0 kernel/notifier.c:93
raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:2074 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2112 [inline]
call_netdevice_notifiers net/core/dev.c:2126 [inline]
unregister_netdevice_many_notify+0xe3f/0x1c30 net/core/dev.c:11533
unregister_netdevice_many net/core/dev.c:11595 [inline]
default_device_exit_batch+0x828/0x8c0 net/core/dev.c:12166
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x744/0xc90 net/core/net_namespace.c:642
process_one_work kernel/workqueue.c:3261 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342
worker_thread+0xc51/0x1370 kernel/workqueue.c:3423
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: 139579 callbacks suppressed
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:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:5e:0b:a0:d1:7f:6a, 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 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:aa:aa:aa:aa:aa:0c, vlan:0)