INFO: task syz.1.834:2751 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.834 state:D stack:0 pid:2751 tgid:2751 ppid:295 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x369/0x650 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x540 kernel/rcu/tree.c:4657 netdev_run_todo+0x118/0xce0 net/core/dev.c:10900 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xc5/0x150 drivers/net/tun.c:3520 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e5/0x260 kernel/task_work.c:246 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9ad/0x2720 kernel/exit.c:954 do_group_exit+0x229/0x2f0 kernel/exit.c:1096 get_signal+0x1398/0x14e0 kernel/signal.c:2933 arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb13335d68e RSP: 002b:00007fb13417ff58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007fb1341806c0 RCX: 00007fb13335d68e RDX: 00007fb13417ffb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fb133432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb133616128 R14: 00007fb133616090 R15: 00007ffcc2cd43b8 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 d58365df94cd5f4886b4f3ec3f08a458f2157066 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: 33 Comm: rcuop/1 Not tainted syzkaller #0 d58365df94cd5f4886b4f3ec3f08a458f2157066 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__find_rr_leaf+0x24e/0x840 net/ipv6/route.c:873 Code: 7d 00 00 0f 85 3a 01 00 00 4d 8d a6 c0 00 00 00 4c 89 e7 44 89 fe 8b 54 24 34 8b 4d 10 4c 8b 45 20 4c 8b 4d 18 e8 62 07 00 00 <84> c0 0f 84 b2 00 00 00 e8 45 c1 87 fc 49 bd 00 00 00 00 00 fc ff RSP: 0018:ffffc900002302c0 EFLAGS: 00000286 RAX: 0000000000000000 RBX: 1ffff1102691fb8c RCX: ffff888103679300 RDX: 0000000000000100 RSI: 00000000fffffffd RDI: 00000000fffffffd RBP: ffffc90000230418 R08: ffffc90000230540 R09: ffffc90000230550 R10: ffffc900002306b0 R11: fffff520000460da R12: ffff8881348fdcc0 R13: ffff8881348fdcb0 R14: ffff8881348fdc00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff412514ff8 CR3: 000000012f1ec000 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:626 [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:5789 [inline] __netif_receive_skb net/core/dev.c:5902 [inline] process_backlog+0x44b/0xad0 net/core/dev.c:6238 __napi_poll+0xd0/0x610 net/core/dev.c:6889 napi_poll net/core/dev.c:6958 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7080 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 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch+0x5d9/0xd40 kernel/rcu/tree.c:2594 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline] rcu_nocb_cb_kthread+0x524/0xb30 kernel/rcu/tree_nocb.h:957 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: 82105 callbacks suppressed 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:e6:99:2b:92:d0:e9, vlan:0) 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! 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! 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! bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 102125 callbacks suppressed 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:e6:99:2b:92:d0:e9, vlan:0) 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! 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! 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! bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)