INFO: task syz.2.1405:4741 blocked for more than 123 seconds. Not tainted 6.12.30-syzkaller-gfc2476d0896a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1405 state:D stack:0 pid:4741 tgid:4741 ppid:293 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x132b/0x1e00 kernel/sched/core.c:7789 __schedule_loop kernel/sched/core.c:7870 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7885 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4642 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10864 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:3517 __fput+0x1fb/0xa00 fs/file_table.c:431 ____fput+0x20/0x30 fs/file_table.c:459 task_work_run+0x1e3/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9b4/0x2630 kernel/exit.c:944 do_group_exit+0x22a/0x300 kernel/exit.c:1094 get_signal+0x139d/0x14f0 kernel/signal.c:2934 arch_do_signal_or_restart+0x96/0x720 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+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fd1dbbc3209 RSP: 002b:00007ffc78f41688 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3 RAX: fffffffffffffff4 RBX: 00007fd1dbb45600 RCX: 00007fd1dbbc3209 RDX: 00007fd1dbb45600 RSI: 0000000000000058 RDI: 00007ffc78f416d0 RBP: 00007fd1dca096c0 R08: 00007fd1dca096c0 R09: 00007ffc78f417b7 R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8 R13: 000000000000000b R14: 00007ffc78f416d0 R15: 00007ffc78f417b8 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-gfc2476d0896a #0 e1e9364838a23ddd1cd40ddd4d9250930b5d8506 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/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+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 4744 Comm: syz-executor Not tainted 6.12.30-syzkaller-gfc2476d0896a #0 e1e9364838a23ddd1cd40ddd4d9250930b5d8506 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:update_stack_state+0x2b2/0x4b0 arch/x86/kernel/unwind_frame.c:261 Code: 84 ae 97 00 49 83 3e 00 74 2b 44 3b 6d ac 75 25 48 8b 45 a0 48 39 45 b0 73 1b 31 db 89 d8 48 81 c4 98 00 00 00 5b 41 5c 41 5d <41> 5e 41 5f 5d c3 cc cc cc cc cc 4c 8b 6d 80 4d 85 ed 4c 89 75 b8 RSP: 0018:ffffc90000007450 EFLAGS: 00000282 RAX: 0000000000007501 RBX: ffffc90000007568 RCX: ffffc90000007601 RDX: ffffc900000075f0 RSI: 1ffff92000000eae RDI: ffffc900000075c0 RBP: ffffc90000007460 R08: ffffc90000007500 R09: 0000000000000000 R10: ffffc90000007568 R11: fffff52000000eb9 R12: 0000000000000000 R13: 1ffff92000000eb8 R14: ffffc900000075a8 R15: 1ffff92000000eb5 FS: 000055556e0ff500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f001d1f84c0 CR3: 000000012d5ac000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x3c2/0x750 arch/x86/kernel/unwind_frame.c:315 __unwind_start+0x34d/0x410 arch/x86/kernel/unwind_frame.c:417 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf3/0x170 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x4a/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2413 [inline] slab_free mm/slub.c:4662 [inline] kmem_cache_free+0x1c1/0x510 mm/slub.c:4769 kfree_skbmem net/core/skbuff.c:-1 [inline] __kfree_skb+0x18f/0x210 net/core/skbuff.c:1215 sk_skb_reason_drop+0xd8/0x310 net/core/skbuff.c:1252 kfree_skb_reason include/linux/skbuff.h:1271 [inline] kfree_skb include/linux/skbuff.h:1280 [inline] ip6_mc_input+0x4f3/0x670 net/ipv6/ip6_input.c:587 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish+0x344/0x3c0 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:317 [inline] ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5757 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] process_backlog+0x44b/0xae0 net/core/dev.c:6202 __napi_poll+0xd3/0x610 net/core/dev.c:6853 napi_poll net/core/dev.c:6922 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7044 handle_softirqs+0x1ae/0x630 kernel/softirq.c:603 __do_softirq+0xf/0x16 kernel/softirq.c:641 do_softirq+0xa6/0x100 kernel/softirq.c:485 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412 __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] rt6_uncached_list_flush_dev net/ipv6/route.c:193 [inline] rt6_disable_ip+0x7b7/0x870 net/ipv6/route.c:4934 addrconf_ifdown+0x161/0x1940 net/ipv6/addrconf.c:3902 addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1 notifier_call_chain+0x10e/0x2c0 kernel/notifier.c:93 raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461 call_netdevice_notifiers_info net/core/dev.c:2067 [inline] call_netdevice_notifiers_extack net/core/dev.c:2105 [inline] call_netdevice_notifiers net/core/dev.c:2119 [inline] unregister_netdevice_many_notify+0xe32/0x1bd0 net/core/dev.c:11485 unregister_netdevice_many+0x1d/0x30 net/core/dev.c:11547 setup_net+0x5cc/0x990 net/core/net_namespace.c:383 copy_net_ns+0x513/0xa30 net/core/net_namespace.c:510 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x126/0x180 kernel/nsproxy.c:228 ksys_unshare+0x4fe/0x880 kernel/fork.c:3351 __do_sys_unshare kernel/fork.c:3422 [inline] __se_sys_unshare kernel/fork.c:3420 [inline] __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3420 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f76999901a7 Code: 73 01 c3 48 c7 c1 a8 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd38269a98 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f7699bb5f40 RCX: 00007f76999901a7 RDX: 0000000000000005 RSI: 00007ffd38269960 RDI: 0000000040000000 RBP: 00007f7699bb6738 R08: 00007f769a6e7d60 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 net_ratelimit: 48732 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:c2:9f:d7:f3:47:75, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:10:20:10:00:00:00, 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:10:20:10:00:00:00, 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:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c2:9f:d7:f3:47:75, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c2:9f:d7:f3:47:75, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:10:20:10:00:00:00, vlan:0) net_ratelimit: 61553 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, 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:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c2:9f:d7:f3:47:75, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:c2:9f:d7:f3:47:75, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:10:20:10:00:00:00, 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:10:20:10:00:00:00, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)