INFO: task syz-executor:432 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:432 tgid:432 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: 0033:0x7f38fc59f167 RSP: 002b:00007ffc1ef51558 EFLAGS: 00000206 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f38fc825f40 RCX: 00007f38fc59f167 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f38fc8267b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffc1ef51798 R15: 0000000000000000 INFO: task syz-executor:433 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:433 tgid:433 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 ipip_init_net+0x2d/0x40 net/ipv4/ipip.c:601 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: 0033:0x7f29e559f167 RSP: 002b:00007ffd10dbb7f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f29e5825f40 RCX: 00007f29e559f167 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f29e58267b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffd10dbba38 R15: 0000000000000000 INFO: task syz-executor:435 blocked for more than 127 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:435 tgid:435 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 ipip_init_net+0x2d/0x40 net/ipv4/ipip.c:601 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: 0033:0x7f94e639f167 RSP: 002b:00007fff0b289dc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f94e6625f40 RCX: 00007f94e639f167 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f94e66267b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007fff0b28a008 R15: 0000000000000000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a4a563d0c71b2f3eba821a1af94cbf4bdc8174ca Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 a4a563d0c71b2f3eba821a1af94cbf4bdc8174ca Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: netns cleanup_net RIP: 0010:0xffffffffa0000cec Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 41 ff e3 cc 41 ff e3 cc 41 ff e3 cc <41> ff e3 cc 41 ff e3 cc 41 ff e3 cc 41 ff e3 cc 41 ff e3 cc cc cc RSP: 0018:ffffc9000022fc20 EFLAGS: 00000257 RAX: ffffffff81dc797b RBX: ffffc9000022fce0 RCX: 0000000000045f00 RDX: ffffc90000230401 RSI: ffffffff81dc797b RDI: ffffc9000022fce0 RBP: ffffc9000022fcb0 R08: ffffc9000022fcf0 R09: ffffc9000022fce8 R10: 0000000000000000 R11: ffffffff81759ed0 R12: ffff888103651300 R13: 1ffff110206ca320 R14: ffffffff81759ed0 R15: ffffc9000022fc28 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055688a8ecaf8 CR3: 000000010c37c000 CR4: 00000000003526b0 Call Trace: stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x240 mm/page_owner.c:174 __set_page_owner+0x8e/0x600 mm/page_owner.c:338 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863 prep_new_page+0x2d/0x180 mm/page_alloc.c:1871 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1 allocate_slab+0x69/0x430 mm/slub.c:2687 new_slab mm/slub.c:2741 [inline] ___slab_alloc+0x591/0x8c0 mm/slub.c:3934 __slab_alloc mm/slub.c:4025 [inline] __slab_alloc_node mm/slub.c:4078 [inline] slab_alloc_node mm/slub.c:4239 [inline] kmem_cache_alloc_noprof+0x290/0x410 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+0xfc1/0x3a70 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+0x744/0xc90 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: 97936 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:56:19:2f:f7:91:3d, 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 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:56:19:2f:f7:91:3d, 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:56:19:2f:f7:91:3d, 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:56:19:2f:f7:91:3d, 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:56:19:2f:f7:91:3d, vlan:0)