INFO: task syz.0.2002:6192 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2002 state:D stack:0 pid:6192 tgid:6190 ppid:292 flags:0x00004204
Call Trace:
context_switch kernel/sched/core.c:6016 [inline]
__schedule+0x134f/0x1ea0 kernel/sched/core.c:7864
__schedule_loop kernel/sched/core.c:7945 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7960
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8017
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285
rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589
netdev_run_todo+0x118/0xce0 net/core/dev.c:10887
rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
setup_net+0x5ea/0x9b0 net/core/net_namespace.c:384
copy_net_ns+0x512/0xa30 net/core/net_namespace.c:510
create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x502/0x880 kernel/fork.c:3369
__do_sys_unshare kernel/fork.c:3440 [inline]
__se_sys_unshare kernel/fork.c:3438 [inline]
__x64_sys_unshare+0x3c/0x50 kernel/fork.c:3438
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: 0033:0x7f35d2b9c799
RSP: 002b:00007f35d39cb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f35d2e15fa0 RCX: 00007f35d2b9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007f35d2c32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35d2e16038 R14: 00007f35d2e15fa0 R15: 00007ffc497037d8
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 67ca8ba3aa6540f07d3e691c9ce537bd6d0a0d70
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+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: 4561 Comm: kworker/u8:32 Not tainted syzkaller #0 67ca8ba3aa6540f07d3e691c9ce537bd6d0a0d70
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: netns cleanup_net
RIP: 0010:__sanitizer_cov_trace_cmp4+0x86/0x90 kernel/kcov.c:289
Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 <5d> e9 84 1b 1a 04 cc 0f 1f 00 b8 53 90 f8 6a 90 90 90 90 90 90 90
RSP: 0018:ffffc9000022ff80 EFLAGS: 00000246
RAX: ffffffff84d7e70f RBX: dffffc0000000000 RCX: 0000000000000100
RDX: ffff88811e47a600 RSI: 0000000000001c48 RDI: 00000000000005a8
RBP: ffffc9000022ff80 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000045ff0 R12: ffff8881541d78d0
R13: 00000000000005a8 R14: ffff8881541d5000 R15: 0000000000001c48
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f31cbb8c070 CR3: 000000010cbc6000 CR4: 00000000003526b0
DR0: 0000000000000004 DR1: 0000000000000002 DR2: 0000000000000006
DR3: 0000000000009a47 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
inet_frag_queue_insert+0x21f/0x7f0 net/ipv4/inet_fragment.c:426
ip6_frag_queue net/ipv6/reassembly.c:193 [inline]
ipv6_frag_rcv+0x1403/0x2590 net/ipv6/reassembly.c:388
ip6_protocol_deliver_rcu+0xbc8/0x12f0 net/ipv6/ip6_input.c:436
ip6_input_finish net/ipv6/ip6_input.c:481 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
ip6_input+0x1cd/0x3a0 net/ipv6/ip6_input.c:490
ip6_mc_input+0x35a/0x6c0 net/ipv6/ip6_input.c:584
dst_input include/net/dst.h:469 [inline]
ip6_rcv_finish+0x363/0x3e0 net/ipv6/ip6_input.c:79
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]
netif_receive_skb_internal net/core/dev.c:5975 [inline]
netif_receive_skb+0x147/0x7b0 net/core/dev.c:6034
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+0x1317/0x1760 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+0xfb1/0x3ab0 net/core/dev.c:5670
__netif_receive_skb_one_core net/core/dev.c:5774 [inline]
__netif_receive_skb net/core/dev.c:5889 [inline]
process_backlog+0x3e5/0xad0 net/core/dev.c:6225
__napi_poll+0xd0/0x610 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+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+0x10b/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]
dev_close_many+0x33b/0x4f0 net/core/dev.c:1667
unregister_netdevice_many_notify+0x4bb/0x1c30 net/core/dev.c:11482
unregister_netdevice_many+0x1d/0x30 net/core/dev.c:11570
cleanup_net+0x643/0xc90 net/core/net_namespace.c:637
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
kthread+0x2c6/0x370 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: 173253 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
net_ratelimit: 214318 callbacks suppressed
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)