INFO: task kworker/u8:1:13 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:0 pid:13 tgid:13 ppid:2 flags:0x00004000 Workqueue: events_unbound linkwatch_event 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 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79 linkwatch_event+0x12/0x60 net/core/link_watch.c:285 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+0x2c9/0x370 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 INFO: task syz-executor:803 blocked for more than 124 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:803 tgid:803 ppid:1 flags:0x00004004 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 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79 ppp_exit_net+0x12d/0x360 drivers/net/ppp/ppp_generic.c:1158 ops_exit_list net/core/net_namespace.c:173 [inline] setup_net+0x685/0x9b0 net/core/net_namespace.c:388 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:3356 __do_sys_unshare kernel/fork.c:3427 [inline] __se_sys_unshare kernel/fork.c:3425 [inline] __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3425 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: 0033:0x7f79df19da67 RSP: 002b:00007ffd85f2b548 EFLAGS: 00000206 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f79df415f40 RCX: 00007f79df19da67 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f79df4167b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffd85f2b788 R15: 0000000000000000 INFO: task syz-executor:804 blocked for more than 125 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:804 tgid:804 ppid:1 flags:0x00004004 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 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79 fib_net_exit_batch+0x24/0xa0 net/ipv4/fib_frontend.c:1652 ops_exit_list net/core/net_namespace.c:178 [inline] setup_net+0x70c/0x9b0 net/core/net_namespace.c:388 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:3356 __do_sys_unshare kernel/fork.c:3427 [inline] __se_sys_unshare kernel/fork.c:3425 [inline] __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3425 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: 0033:0x7f950319da67 RSP: 002b:00007ffcd14f8928 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f9503415f40 RCX: 00007f950319da67 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f95034167b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffcd14f8b68 R15: 0000000000000000 INFO: task syz-executor:823 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:823 tgid:823 ppid:1 flags:0x00004004 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 rtnl_lock+0x19/0x20 net/core/rtnetlink.c:79 ip_tunnel_init_net+0x30c/0x890 net/ipv4/ip_tunnel.c:1145 ipgre_init_net+0x28/0x30 net/ipv4/ip_gre.c:1070 ops_init+0x1b2/0x5d0 net/core/net_namespace.c:139 setup_net+0x227/0x9b0 net/core/net_namespace.c:356 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:3356 __do_sys_unshare kernel/fork.c:3427 [inline] __se_sys_unshare kernel/fork.c:3425 [inline] __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3425 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: 0033:0x7f477619da67 RSP: 002b:00007ffce4bf4b98 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f4776415f40 RCX: 00007f477619da67 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f47764167b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffce4bf4dd8 R15: 0000000000000000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a88889f1fd4bd040639a1a4060abea1bc20e1fef 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+0x2c9/0x370 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: 46 Comm: kworker/u8:2 Not tainted syzkaller #0 a88889f1fd4bd040639a1a4060abea1bc20e1fef Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: netns cleanup_net RIP: 0010:__kernel_text_address+0x2d/0x40 kernel/extable.c:92 Code: 00 55 48 89 e5 53 48 89 fb e8 3f 00 00 00 48 81 fb 00 50 f5 87 0f 93 c1 48 81 fb 05 b0 07 88 0f 92 c2 20 ca 08 c2 0f b6 c2 5b <5d> e9 7d c5 48 04 cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 00 00 RSP: 0018:ffffc9000022ff70 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc9000022fff0 RCX: 000000000022ff00 RDX: ffffc90000230301 RSI: 1ffff92000045ff6 RDI: ffffffff81db710d RBP: ffffc9000022ff70 R08: ffffc90000230070 R09: ffffc90000230068 R10: 0000000000000002 R11: ffffffff8175cdf0 R12: ffff888105245f00 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000045ffe FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f180240e2e1 CR3: 000000010cf42000 CR4: 00000000003526b0 Call Trace: unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_frame.c:19 arch_stack_walk+0x10a/0x170 arch/x86/kernel/stacktrace.c:26 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+0x4a/0x60 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:4821 kfree_skbmem net/core/skbuff.c:-1 [inline] __kfree_skb+0x18f/0x210 net/core/skbuff.c:1203 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1240 kfree_skb_reason include/linux/skbuff.h:1271 [inline] kfree_skb include/linux/skbuff.h:1280 [inline] ip6_mc_input+0x516/0x6c0 net/ipv6/ip6_input.c:587 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish+0x360/0x3e0 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+0xfae/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+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:11508 unregister_netdevice_many net/core/dev.c:11570 [inline] default_device_exit_batch+0x828/0x8c0 net/core/dev.c:12053 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x747/0xc90 net/core/net_namespace.c:642 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+0x2c9/0x370 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: 98934 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:fd:4c:3c:53:8f, 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:d6:fd:4c:3c:53:8f, 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:d6:fd:4c:3c:53:8f, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:fd:4c:3c:53:8f, 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:d6:fd:4c:3c:53:8f, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)