INFO: task kworker/1:3:341 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:0 pid:341 tgid:341 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+0x7d5/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 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 INFO: task syz.7.993:3554 blocked for more than 125 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.993 state:D stack:0 pid:3554 tgid:3551 ppid:3283 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+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e3/0x250 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] __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: 0033:0x7fc094b8e7eb RSP: 002b:00007fc095a70490 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007fc095a70be0 RCX: 00007fc094b8e7eb RDX: 00007fc095a70be0 RSI: 000000004020ae46 RDI: 0000000000000008 RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000001 R13: 0000200000fe9000 R14: 0000200000fe8000 R15: 00000000fec00000 INFO: task syz.6.995:3557 blocked for more than 126 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.995 state:D stack:0 pid:3557 tgid:3557 ppid:2634 flags:0x00004004 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+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e3/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f311898ebe9 RSP: 002b:00007ffcf56ce578 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f3118bc7da0 RCX: 00007f311898ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f3118bc7da0 R08: 0000000000000000 R09: 00000022f56ce86f R10: 00007f3118bc7cb0 R11: 0000000000000246 R12: 0000000000021472 R13: 00007ffcf56ce670 R14: ffffffffffffffff R15: 00007ffcf56ce690 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 3aa8e93a75ec4fb080c21ea51d8727149e6cfac5 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 568 Comm: kworker/0:5 Not tainted syzkaller #0 3aa8e93a75ec4fb080c21ea51d8727149e6cfac5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:stack_trace_consume_entry+0xa6/0x2a0 kernel/stacktrace.c:93 Code: 41 0f b6 04 17 84 c0 0f 85 8d 01 00 00 45 89 34 24 b0 01 e9 a2 00 00 00 31 c0 e9 9b 00 00 00 48 89 f8 48 c1 e8 03 80 3c 10 00 <48> 89 75 c0 74 2b 49 89 ff 49 89 d4 4c 89 45 c8 4d 89 ce 4c 89 55 RSP: 0018:ffffc90000006f50 EFLAGS: 00000246 RAX: 1ffff92000000e0c RBX: 1ffff92000000e0e RCX: 0000000000006f00 RDX: dffffc0000000000 RSI: ffffffff81dbe68f RDI: ffffc90000007060 RBP: ffffc90000006f98 R08: ffffc90000007070 R09: ffffc90000007068 R10: 0000000000000002 R11: ffffffff81744330 R12: ffffc9000000706c R13: 1ffff92000000e0d R14: 0000000000000000 R15: 1ffff92000000e0d FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005604324e4b98 CR3: 00000000072a8000 CR4: 00000000003526b0 Call Trace: arch_stack_walk+0x12d/0x170 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:69 kasan_save_free_info+0x4a/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:248 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:265 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2418 [inline] slab_free mm/slub.c:4672 [inline] kmem_cache_free+0x1c1/0x510 mm/slub.c:4779 skb_kfree_head net/core/skbuff.c:1082 [inline] skb_free_head net/core/skbuff.c:1096 [inline] skb_release_data+0x72f/0x9a0 net/core/skbuff.c:1123 skb_release_all net/core/skbuff.c:1188 [inline] __kfree_skb+0x62/0x210 net/core/skbuff.c:1202 consume_skb+0x65/0x1a0 net/core/skbuff.c:1434 netlink_broadcast_filtered+0x10e1/0x11f0 net/netlink/af_netlink.c:1540 nlmsg_multicast_filtered include/net/netlink.h:1125 [inline] nlmsg_multicast include/net/netlink.h:1144 [inline] nlmsg_notify+0xf1/0x1b0 net/netlink/af_netlink.c:2598 rtnl_notify+0x9e/0xd0 net/core/rtnetlink.c:786 fdb_notify+0xce/0x150 net/bridge/br_fdb.c:206 br_fdb_update+0x4b7/0x680 net/bridge/br_fdb.c:941 br_handle_frame_finish+0x39c/0x1720 net/bridge/br_input.c:141 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:5651 __netif_receive_skb_one_core net/core/dev.c:5755 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] process_backlog+0x3e5/0xae0 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_write_unlock_bh include/linux/rwlock_api_smp.h:281 [inline] _raw_write_unlock_bh+0x33/0x70 kernel/locking/spinlock.c:366 neigh_periodic_work+0xa73/0xbc0 net/core/neighbour.c:1019 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 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 net_ratelimit: 106830 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: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: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:42:d3:eb:53:f5:dc, 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)