INFO: task kworker/0:2:296 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:0 pid:296 tgid:296 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:6016 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7864 __schedule_loop kernel/sched/core.c:7945 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7960 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8017 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x540 kernel/rcu/tree.c:4589 netdev_run_todo+0x118/0xce0 net/core/dev.c:10887 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 unregister_netdev+0x166/0x1d0 net/core/dev.c:11589 usbnet_disconnect+0xd5/0x3a0 drivers/net/usb/usbnet.c:1653 usb_unbind_interface+0x2aa/0xa30 drivers/usb/core/driver.c:462 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x4c2/0x790 drivers/base/dd.c:1295 device_release_driver+0x1d/0x30 drivers/base/dd.c:1318 bus_remove_device+0x359/0x380 drivers/base/bus.c:576 device_del+0x581/0xd00 drivers/base/core.c:3881 usb_disable_device+0x3af/0x770 drivers/usb/core/message.c:1418 usb_disconnect+0x322/0x930 drivers/usb/core/hub.c:2353 hub_port_connect drivers/usb/core/hub.c:5414 [inline] hub_port_connect_change drivers/usb/core/hub.c:5714 [inline] port_event drivers/usb/core/hub.c:5878 [inline] hub_event+0x1c7a/0x4700 drivers/usb/core/hub.c:5960 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d1/0x1020 kernel/workqueue.c:3319 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400 kthread+0x2c6/0x370 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.0.546:1955 blocked for more than 125 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.546 state:D stack:0 pid:1955 tgid:1955 ppid:289 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:6016 [inline] __schedule+0x134f/0x1ea0 kernel/sched/core.c:7864 __schedule_loop kernel/sched/core.c:7945 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7960 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 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+0x398/0x420 arch/x86/kvm/x86.c:12970 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+0x1e8/0x260 kernel/task_work.c:246 resume_user_mode_work+0x35/0x50 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+0x63/0xb0 kernel/entry/common.c:218 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f933959c799 RSP: 002b:00007fffca3b6c98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fffca3b6d80 RCX: 00007f933959c799 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000001da87 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2dc20000 R11: 0000000000000246 R12: 00007fffca3b6dc0 R13: 00007f9339815fac R14: 000000000001e6eb R15: 00007f9339815fa0 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 f5ac747b36c456989d7181d0133b7a324c782226 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0x2c6/0x370 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 20 Comm: rcuop/0 Not tainted syzkaller #0 f5ac747b36c456989d7181d0133b7a324c782226 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:stack_trace_consume_entry+0xa/0x2a0 kernel/stacktrace.c:83 Code: 2d 04 cc e8 a8 1e 2b 04 0f 1f 84 00 00 00 00 00 b8 e3 b0 ae 28 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 ec 20 48 ba 00 00 00 00 00 fc ff df 4c RSP: 0018:ffffc90000006c50 EFLAGS: 00000257 RAX: ffffffff84813535 RBX: ffffc90000006d20 RCX: 0000000000006c00 RDX: ffffc90000007b01 RSI: ffffffff84813535 RDI: ffffc90000006d20 RBP: ffffc90000006c58 R08: ffffc90000006d30 R09: ffffc90000006d28 R10: 0000000000000000 R11: ffffffff8175d5f0 R12: ffff888103662600 R13: 000000000114ab01 R14: ffffffff8175d5f0 R15: ffffc90000006c68 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc70df84c0 CR3: 0000000107b98000 CR4: 00000000003526b0 Call Trace: arch_stack_walk+0x129/0x170 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:49 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:70 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565 unpoison_slab_object mm/kasan/common.c:321 [inline] __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347 kasan_slab_alloc include/linux/kasan.h:251 [inline] slab_post_alloc_hook mm/slub.c:4202 [inline] slab_alloc_node mm/slub.c:4251 [inline] kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260 dst_alloc+0x13c/0x250 net/core/dst.c:89 rt_dst_alloc net/ipv4/route.c:1647 [inline] ip_route_input_slow net/ipv4/route.c:2385 [inline] ip_route_input_rcu+0x1a0e/0x2700 net/ipv4/route.c:2499 ip_route_input_noref+0xd4/0x150 net/ipv4/route.c:2510 arp_process+0x908/0x1790 net/ipv4/arp.c:841 NF_HOOK+0x17e/0x1e0 include/linux/netfilter.h:317 arp_rcv+0x2f8/0x490 net/ipv4/arp.c:992 __netif_receive_skb_one_core net/core/dev.c:5776 [inline] __netif_receive_skb net/core/dev.c:5889 [inline] netif_receive_skb_internal net/core/dev.c:5975 [inline] netif_receive_skb+0x22a/0x7b0 net/core/dev.c:6034 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70 br_handle_frame_finish+0x1317/0x1760 net/bridge/br_input.c:221 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+0xfae/0x3ab0 net/core/dev.c:5670 __netif_receive_skb_one_core net/core/dev.c:5774 [inline] __netif_receive_skb net/core/dev.c:5889 [inline] process_backlog+0x3e5/0xad0 net/core/dev.c:6225 __napi_poll+0xd3/0x610 net/core/dev.c:6876 napi_poll net/core/dev.c:6945 [inline] net_rx_action+0x5ea/0xd80 net/core/dev.c:7067 handle_softirqs+0x1ad/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+0x2c6/0x370 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: 103005 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:36:65:73:d9:db:20, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)