INFO: task kworker/0:4:401 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:0 pid:401 tgid:401 ppid:2 flags:0x00004000 Workqueue: events fqdir_free_fn 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_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:4657 fqdir_free_fn+0x36/0x150 net/ipv4/inet_fragment.c:167 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d2/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2ca/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 INFO: task syz.9.11007:32403 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.11007 state:D stack:0 pid:32403 tgid:32403 ppid:32337 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:12923 kvm_destroy_vm virt/kvm/kvm_main.c:1355 [inline] kvm_put_kvm+0xb04/0x12c0 virt/kvm/kvm_main.c:1392 kvm_vm_release+0x47/0x70 virt/kvm/kvm_main.c:1415 __fput+0x1fb/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9bc/0x2630 kernel/exit.c:953 do_group_exit+0x22a/0x300 kernel/exit.c:1095 get_signal+0x139d/0x14f0 kernel/signal.c:2933 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] irqentry_exit_to_user_mode+0x4e/0xb0 kernel/entry/common.c:231 irqentry_exit+0x16/0x60 kernel/entry/common.c:334 exc_general_protection+0x15a/0x1f0 arch/x86/kernel/traps.c:747 asm_exc_general_protection+0x2b/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7f315f98efd1 RSP: 002b:0000200000000280 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f315fbe5fa0 RCX: 00007f315f98efc9 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000002000000 RBP: 00007f315fa11f91 R08: 00002000000003c0 R09: 00002000000003c0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f315fbe6038 R14: 00007f315fbe5fa0 R15: 00007ffe0a2f4338 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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+0x2ca/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: 20 Comm: rcuop/0 Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:netif_skb_features+0xb29/0x14f0 net/core/dev.c:3656 Code: e8 6c 91 16 fd 48 b8 e5 ff 00 00 f8 ff ff ff 49 21 c6 48 bb 00 00 00 00 00 fc ff df eb 0c e8 4e 91 16 fd eb 05 e8 47 91 16 fd <48> c7 84 24 80 00 00 00 0e 36 e0 45 49 c7 04 1c 00 00 00 00 65 48 RSP: 0018:ffffc90000230060 EFLAGS: 00000246 RAX: ffffffff846f6c56 RBX: dffffc0000000000 RCX: ffff888103660000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000230170 R08: ffff888103660000 R09: 0000000000000002 R10: 000000000000a888 R11: 0000000000000100 R12: 1ffff9200004601c R13: ffff888195c64300 R14: 000061164fdd09e9 R15: 000000000000dd86 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9d03518740 CR3: 0000000124d72000 CR4: 00000000003526b0 Call Trace: validate_xmit_skb+0xe2/0xdb0 net/core/dev.c:3752 __dev_queue_xmit+0x1512/0x3790 net/core/dev.c:4518 dev_queue_xmit include/linux/netdevice.h:3141 [inline] br_dev_queue_push_xmit+0x553/0x6d0 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:317 [inline] br_forward_finish net/bridge/br_forward.c:66 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] __br_forward+0x25c/0x390 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x67e/0x730 net/bridge/br_forward.c:245 br_handle_frame_finish+0x12bb/0x1720 net/bridge/br_input.c:215 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+0xf4b/0x3940 net/core/dev.c:5663 __netif_receive_skb_one_core net/core/dev.c:5767 [inline] __netif_receive_skb net/core/dev.c:5882 [inline] process_backlog+0x3e5/0xae0 net/core/dev.c:6218 __napi_poll+0xd3/0x610 net/core/dev.c:6869 napi_poll net/core/dev.c:6938 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7060 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 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2594 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline] rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957 kthread+0x2ca/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: 90105 callbacks suppressed 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:56:f4:f3:34:41:7e, 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) 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:56:f4:f3:34:41:7e, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 101748 callbacks suppressed 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) 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: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 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)