INFO: task syz-executor:4352 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 991092e6aacd45c89fe3e25b50ff7d10cec51463
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 4379 Comm: syz-executor Not tainted syzkaller #0 991092e6aacd45c89fe3e25b50ff7d10cec51463
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:is_last_frame arch/x86/kernel/unwind_frame.c:87 [inline]
RIP: 0010:is_last_task_frame arch/x86/kernel/unwind_frame.c:156 [inline]
RIP: 0010:unwind_next_frame+0xa3/0x6b0 arch/x86/kernel/unwind_frame.c:276
Code: b6 04 30 84 c0 0f 85 75 05 00 00 41 f6 04 24 03 0f 85 94 04 00 00 48 8d 7b 38 48 89 f8 48 c1 e8 03 48 89 45 c0 42 80 3c 30 00 <74> 05 e8 d6 91 9b 00 4c 8b 63 38 4c 8d 6b 28 4c 89 e8 48 c1 e8 03
RSP: 0000:ffffc90000230288 EFLAGS: 00000246
RAX: 1ffff92000046064 RBX: ffffc900002302e8 RCX: 0000000000046000
RDX: dffffc0000000000 RSI: ffffffff84f60771 RDI: ffffc90000230320
RBP: ffffc900002302d8 R08: ffffc900002303b0 R09: ffffc900002303a8
R10: 000000000000000a R11: ffffffff81759b00 R12: ffff888127691300
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  000055558d1a6500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa2807eaff8 CR3: 000000014cbe4000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25
 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_free_info+0x44/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:249 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:266
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2445 [inline]
 slab_free mm/slub.c:4714 [inline]
 kmem_cache_free+0x1bd/0x4f0 mm/slub.c:4825
 kfree_skbmem net/core/skbuff.c:-1 [inline]
 __kfree_skb+0x18f/0x210 net/core/skbuff.c:1200
 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1237
 kfree_skb_reason include/linux/skbuff.h:1303 [inline]
 icmpv6_rcv+0x1140/0x1800 net/ipv6/icmp.c:-1
 ip6_protocol_deliver_rcu+0xbc0/0x1270 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+0x1c3/0x3a0 net/ipv6/ip6_input.c:490
 ip6_mc_input+0x333/0x680 net/ipv6/ip6_input.c:584
 dst_input include/net/dst.h:469 [inline]
 ip6_rcv_finish+0x341/0x3c0 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:5801 [inline]
 __netif_receive_skb net/core/dev.c:5914 [inline]
 process_backlog+0x472/0xaf0 net/core/dev.c:6250
 __napi_poll+0xd0/0x600 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
 </IRQ>
 <TASK>
 __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+0x1d/0x30 net/core/dev.c:11595
 setup_net+0x5e5/0x9b0 net/core/net_namespace.c:383
 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: 0033:0x7f0f6af9f127
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcdf4e9e88 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f0f6b225f40 RCX: 00007f0f6af9f127
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f0f6b2267b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffcdf4ea0c8 R15: 0000000000000000
 </TASK>
net_ratelimit: 155683 callbacks suppressed
ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0!
ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge!
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge!
ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0!
ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge!
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge!
ICMPv6: NA: aa:aa:aa:aa:aa:0c advertised our address fe80::a8aa:aaff:feaa:aa0c on bridge0!
ICMPv6: NA: aa:aa:aa:aa:aa:1c advertised our address fe80::a8aa:aaff:feaa:aa1c on veth1_to_bridge!