INFO: task syz-executor:730 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:730 tgid:730 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6027 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7894 __schedule_loop kernel/sched/core.c:7975 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7990 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8047 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __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 ppp_exit_net+0x12d/0x360 drivers/net/ppp/ppp_generic.c:1158 ops_exit_list net/core/net_namespace.c:173 [inline] setup_net+0x688/0x9b0 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+0x503/0x8d0 kernel/fork.c:3374 __do_sys_unshare kernel/fork.c:3457 [inline] __se_sys_unshare kernel/fork.c:3455 [inline] __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3455 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: 0033:0x7fcfae59e127 RSP: 002b:00007fffc142ce28 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007fcfae815f40 RCX: 00007fcfae59e127 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007fcfae8167b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007fffc142d068 R15: 0000000000000000 INFO: task syz-executor:745 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:745 tgid:745 ppid:1 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6027 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7894 __schedule_loop kernel/sched/core.c:7975 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7990 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8047 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rtnl_lock net/core/rtnetlink.c:79 [inline] rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6675 netlink_rcv_skb+0x259/0x4f0 net/netlink/af_netlink.c:2545 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x68d/0x700 net/socket.c:2216 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xe9/0x100 net/socket.c:2224 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45 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: 0033:0x7f1578557fd7 RSP: 002b:00007fff29a9cb70 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055558b3f6500 RCX: 00007f1578557fd7 RDX: 000000000000002c RSI: 00007f1579344670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fff29a9cbd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f1579344670 R15: 0000000000000000 INFO: task syz-executor:747 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:747 tgid:747 ppid:1 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:6027 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7894 __schedule_loop kernel/sched/core.c:7975 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7990 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8047 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rtnl_lock net/core/rtnetlink.c:79 [inline] rtnetlink_rcv_msg+0x79e/0xa40 net/core/rtnetlink.c:6675 netlink_rcv_skb+0x259/0x4f0 net/netlink/af_netlink.c:2545 rtnetlink_rcv+0x20/0x30 net/core/rtnetlink.c:6696 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x8c3/0xa60 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x7fe/0xb10 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x68d/0x700 net/socket.c:2216 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xe9/0x100 net/socket.c:2224 x64_sys_call+0x2c2c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:45 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: 0033:0x7ff062957fd7 RSP: 002b:00007ffccfce47f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055557b8e0500 RCX: 00007ff062957fd7 RDX: 000000000000002c RSI: 00007ff063744670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffccfce4854 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000000 R14: 00007ff063744670 R15: 0000000000000000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 455e6e6e4058e005312aabb3f62c8d3b97c06770 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 455e6e6e4058e005312aabb3f62c8d3b97c06770 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: netns cleanup_net RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 99 05 48 89 de e8 30 86 54 00 5b 5d e9 09 dc 22 04 cc cc cc cc cc cc cc cc cc b8 92 a8 c1 eb 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 48 8b 45 08 65 48 8b 0d 3c 23 7d 7e 65 8b RSP: 0018:ffffc9000022fcf8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff11021be980c RCX: 0000000000000100 RDX: ffff888102651300 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000022fe58 R08: ffffc9000022ff80 R09: ffffc9000022ff90 R10: ffffc900002300f0 R11: fffff52000046022 R12: 0000000000000100 R13: dffffc0000000000 R14: ffff88810df4c000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9cd2145000 CR3: 000000010d33a000 CR4: 00000000003526b0 Call Trace: find_rr_leaf net/ipv6/route.c:890 [inline] rt6_select net/ipv6/route.c:934 [inline] fib6_table_lookup+0x2ee/0x9e0 net/ipv6/route.c:2242 ip6_pol_route+0x17a/0x1370 net/ipv6/route.c:2278 ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2335 pol_lookup_func include/net/ip6_fib.h:645 [inline] fib6_rule_lookup+0x4ee/0x6d0 net/ipv6/fib6_rules.c:117 ip6_route_input_lookup net/ipv6/route.c:2347 [inline] ip6_route_input+0x62e/0x8f0 net/ipv6/route.c:2643 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline] ip6_rcv_finish+0x15a/0x3c0 net/ipv6/ip6_input.c:77 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] netif_receive_skb_internal net/core/dev.c:6000 [inline] netif_receive_skb+0x147/0x7b0 net/core/dev.c:6059 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+0x120c/0x17a0 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:5695 __netif_receive_skb_one_core net/core/dev.c:5799 [inline] __netif_receive_skb net/core/dev.c:5914 [inline] process_backlog+0x3e5/0xad0 net/core/dev.c:6250 __napi_poll+0xd3/0x610 net/core/dev.c:6901 napi_poll net/core/dev.c:6970 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7092 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:11533 unregister_netdevice_many net/core/dev.c:11595 [inline] default_device_exit_batch+0x828/0x8c0 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:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 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: 112448 callbacks suppressed 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:ba:c3:bd:6f:dc:76, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:ba:c3:bd:6f:dc:76, 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:1b, 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 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)