INFO: task syz.6.1476:4206 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1476 state:D stack:0 pid:4206 tgid:4205 ppid:1780 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589 kvm_mmu_uninit_tdp_mmu+0x1df/0x210 arch/x86/kvm/mmu/tdp_mmu.c:51 kvm_mmu_uninit_vm+0x27/0x60 arch/x86/kvm/mmu/mmu.c:6572 kvm_arch_destroy_vm+0x383/0x410 arch/x86/kvm/x86.c:12898 kvm_destroy_vm virt/kvm/kvm_main.c:1355 [inline] kvm_put_kvm+0xb04/0x12b0 virt/kvm/kvm_main.c:1391 kvm_vm_release+0x47/0x70 virt/kvm/kvm_main.c:1414 __fput+0x1fb/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e3/0x250 kernel/task_work.c:240 get_signal+0x1307/0x14f0 kernel/signal.c:2706 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: 0033:0x7fd6bbf8e7eb RSP: 002b:00007fd6bce91490 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fd6bce91be0 RCX: 00007fd6bbf8e7eb RDX: 00007fd6bce91be0 RSI: 000000004020ae46 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000011 R13: 0000200000ff9000 R14: 0000200000fe8000 R15: 00000000fec00000 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 ecd017b10525a6fce0a0b730885af6e9bd831db9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 4325 Comm: syz-executor Not tainted syzkaller #0 ecd017b10525a6fce0a0b730885af6e9bd831db9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x70 kernel/kcov.c:217 Code: 8b 45 08 65 48 8b 0c 25 40 eb 04 00 65 8b 15 1c 07 7f 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 ec 0b 00 00 00 <74> 2c 8b 91 c8 0b 00 00 83 fa 02 75 21 48 8b 91 d0 0b 00 00 48 8b RSP: 0018:ffffc900002308c0 EFLAGS: 00000246 RAX: ffffffff84f95be1 RBX: ffffc90000230988 RCX: ffff88810bb92600 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffc90000230988 RBP: ffffc900002308c0 R08: ffff88810bb92600 R09: 0000000000000003 R10: 0000000000000008 R11: 0000000000000100 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff888114220000 R15: dffffc0000000000 FS: 000055555b743500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055eaeff25b90 CR3: 000000011af40000 CR4: 00000000003526b0 Call Trace: __ipv6_addr_type+0x21/0x300 net/ipv6/addrconf_core.c:39 ipv6_addr_type include/net/ipv6.h:546 [inline] rt6_need_strict include/net/ip6_route.h:66 [inline] ip6_route_input_lookup net/ipv6/route.c:2332 [inline] ip6_route_input+0x51a/0x8d0 net/ipv6/route.c:2631 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+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:6206 __napi_poll+0xd3/0x610 net/core/dev.c:6857 napi_poll net/core/dev.c:6926 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7048 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xa6/0x100 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] netif_addr_unlock_bh include/linux/netdevice.h:4581 [inline] dev_mc_flush+0x208/0x240 net/core/dev_addr_lists.c:1036 unregister_netdevice_many_notify+0xee8/0x1bd0 net/core/dev.c:11501 unregister_netdevice_many+0x1d/0x30 net/core/dev.c:11551 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:3352 __do_sys_unshare kernel/fork.c:3423 [inline] __se_sys_unshare kernel/fork.c:3421 [inline] __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3421 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: 0033:0x7f13d3f903e7 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:00007ffce2fe3ec8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f13d41c5f40 RCX: 00007f13d3f903e7 RDX: 0000000000000005 RSI: 00007ffce2fe3d90 RDI: 0000000040000000 RBP: 00007f13d41c67b8 R08: 00007f13d4cf7d60 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 net_ratelimit: 78097 callbacks suppressed 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 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:0c, 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:de:64:6a:81:f6:62, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:de:64:6a:81:f6:62, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)