INFO: task syz-executor:480 blocked for more than 122 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:480 tgid:480 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6060 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7880
__schedule_loop kernel/sched/core.c:7957 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7972
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8029
__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
rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
ip_tunnel_init_net+0x301/0x870 net/ipv4/ip_tunnel.c:1145
ipgre_init_net+0x28/0x30 net/ipv4/ip_gre.c:1070
ops_init+0x302/0x5d0 net/core/net_namespace.c:139
setup_net+0x227/0x9b0 net/core/net_namespace.c:356
copy_net_ns+0x4fc/0xa20 net/core/net_namespace.c:510
create_new_namespaces+0x390/0x6f0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x4f9/0x8f0 kernel/fork.c:3385
__do_sys_unshare kernel/fork.c:3468 [inline]
__se_sys_unshare kernel/fork.c:3466 [inline]
__x64_sys_unshare+0x3c/0x50 kernel/fork.c:3466
x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
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: 0033:0x7f6adaf9f2e7
RSP: 002b:00007ffd8be7e878 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f6adb225f40 RCX: 00007f6adaf9f2e7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f6adb2267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffd8be7eab8 R15: 0000000000000000
INFO: task syz-executor:483 blocked for more than 126 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:483 tgid:483 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:6060 [inline]
__schedule+0x1496/0x20b0 kernel/sched/core.c:7880
__schedule_loop kernel/sched/core.c:7957 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7972
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8029
__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
rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79
ip_tunnel_init_net+0x301/0x870 net/ipv4/ip_tunnel.c:1145
vti_init_net+0x33/0x140 net/ipv4/ip_vti.c:517
ops_init+0x302/0x5d0 net/core/net_namespace.c:139
setup_net+0x227/0x9b0 net/core/net_namespace.c:356
copy_net_ns+0x4fc/0xa20 net/core/net_namespace.c:510
create_new_namespaces+0x390/0x6f0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x4f9/0x8f0 kernel/fork.c:3385
__do_sys_unshare kernel/fork.c:3468 [inline]
__se_sys_unshare kernel/fork.c:3466 [inline]
__x64_sys_unshare+0x3c/0x50 kernel/fork.c:3466
x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
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: 0033:0x7f0ee299f2e7
RSP: 002b:00007ffc3ae317a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f0ee2c25f40 RCX: 00007f0ee299f2e7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f0ee2c267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffc3ae319e8 R15: 0000000000000000
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 89da86cd63dd77ed75a7a6b832383be384370f21
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+0x2c7/0x360 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 89da86cd63dd77ed75a7a6b832383be384370f21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: netns cleanup_net
RIP: 0010:stack_trace_consume_entry+0x130/0x2a0 kernel/stacktrace.c:94
Code: c4 4c 89 cb e8 f1 95 6a 00 49 89 d9 4d 89 e0 4c 89 f2 48 8b 75 c0 49 89 37 41 8b 18 41 0f b6 44 15 00 84 c0 0f 85 42 01 00 00 <41> 3b 19 0f 92 c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d e9 c7
RSP: 0018:ffffc900000071d0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000019 RCX: 0000000000000e00
RDX: dffffc0000000000 RSI: ffffffff8156fa87 RDI: ffffc900000072e0
RBP: ffffc90000007218 R08: ffffc900000072f0 R09: ffffc900000072e8
R10: 0000000000000018 R11: ffffffff81759ed0 R12: ffffc900000072ec
R13: 1ffff92000000e5d R14: ffffc90000007360 R15: ffffc90000007420
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564580929af8 CR3: 000000010c7f0000 CR4: 00000000003526b0
Call Trace:
arch_stack_walk+0x12c/0x170 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:49 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
unpoison_slab_object mm/kasan/common.c:321 [inline]
__kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347
kasan_slab_alloc include/linux/kasan.h:251 [inline]
slab_post_alloc_hook mm/slub.c:4202 [inline]
slab_alloc_node mm/slub.c:4251 [inline]
kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260
skb_clone+0x21d/0x470 net/core/skbuff.c:2079
deliver_clone net/bridge/br_forward.c:125 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x4df/0x720 net/bridge/br_forward.c:237
br_handle_frame_finish+0x1157/0x1620 net/bridge/br_input.c:215
nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
br_handle_frame+0x5a5/0xba0 net/bridge/br_input.c:424
__netif_receive_skb_core+0xfc4/0x3a70 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+0x40b/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_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+0x60d/0x1970 net/ipv6/addrconf.c:3950
addrconf_notify+0x17a/0xeb0 net/ipv6/addrconf.c:-1
notifier_call_chain+0x106/0x2b0 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+0xde1/0x1be0 net/core/dev.c:11533
unregister_netdevice_many net/core/dev.c:11595 [inline]
default_device_exit_batch+0x845/0x8d0 net/core/dev.c:12166
ops_exit_list net/core/net_namespace.c:178 [inline]
cleanup_net+0x741/0xc90 net/core/net_namespace.c:642
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c7/0x360 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: 96725 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:76:a6:de:48:0e:76, 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: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:76:a6:de:48:0e:76, 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)