syzbot


INFO: task hung in wg_destruct (2)

Status: premoderation: reported on 2026/02/26 16:42
Reported-by: syzbot+57529edee469a5bf33f7@syzkaller.appspotmail.com
First crash: 8h09m, last: 8h09m
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 INFO: task hung in wg_destruct 1 1 177d 177d 0/1 auto-obsoleted due to no activity on 2025/12/01 02:17
upstream INFO: task hung in wg_destruct wireguard 1 207 600d 638d 26/29 fixed on 2024/07/09 19:14
linux-6.1 INFO: task hung in wg_destruct 1 9 618d 640d 0/3 auto-obsoleted due to no activity on 2024/09/26 04:00
linux-5.15 INFO: task hung in wg_destruct 1 2 106d 141d 0/3 auto-obsoleted due to no activity on 2026/02/20 18:55
upstream INFO: task hung in wg_destruct (2) wireguard 1 syz done done 141 54d 514d 0/29 upstream: reported syz repro on 2024/09/30 04:20

Sample crash report:
INFO: task kworker/u8:10:4394 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:10   state:D stack:0     pid:4394  tgid:4394  ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843
 __schedule_loop kernel/sched/core.c:7924 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7939
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996
 __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
 wg_destruct+0x236/0x2e0 drivers/net/wireguard/device.c:261
 netdev_run_todo+0xb13/0xce0 net/core/dev.c:10914
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 default_device_exit_batch+0x82d/0x8c0 net/core/dev.c:12054
 ops_exit_list net/core/net_namespace.c:178 [inline]
 cleanup_net+0x747/0xc90 net/core/net_namespace.c:642
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc70/0x10b0 kernel/workqueue.c:3400
 kthread+0x2c9/0x370 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
 </TASK>
INFO: task syz.3.2180:6724 blocked for more than 126 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2180      state:D stack:0     pid:6724  tgid:6722  ppid:292    flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843
 __schedule_loop kernel/sched/core.c:7924 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7939
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996
 __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
 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+0x1e5/0x260 kernel/task_work.c:246
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9e3/0x2650 kernel/exit.c:953
 do_group_exit+0x229/0x2f0 kernel/exit.c:1095
 get_signal+0x1398/0x14e0 kernel/signal.c:2933
 arch_do_signal_or_restart+0xbc/0x760 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+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa60db9c799
RSP: 002b:00007fa60e9e1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 00007fa60de16090 RCX: 00007fa60db9c799
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000009
RBP: 00007fa60dc32bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa60de16128 R14: 00007fa60de16090 R15: 00007ffd89b67788
 </TASK>
INFO: task syz.0.2181:6727 blocked for more than 127 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2181      state:D stack:0     pid:6727  tgid:6727  ppid:4685   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843
 __schedule_loop kernel/sched/core.c:7924 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7939
 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+0x1e5/0x260 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: 0033:0x7f675e19c799
RSP: 002b:00007fff17755c38 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fff17755d20 RCX: 00007f675e19c799
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000043cf4 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b30520000 R11: 0000000000000246 R12: 00007fff17755d60
R13: 00007f675e415fac R14: 0000000000043d64 R15: 00007f675e415fa0
 </TASK>
INFO: task syz.1.2183:6732 blocked for more than 128 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2183      state:D stack:0     pid:6732  tgid:6732  ppid:6690   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5996 [inline]
 __schedule+0x134f/0x1ea0 kernel/sched/core.c:7843
 __schedule_loop kernel/sched/core.c:7924 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7939
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7996
 __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
 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+0x1e5/0x260 kernel/task_work.c:246
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9e3/0x2650 kernel/exit.c:953
 do_group_exit+0x229/0x2f0 kernel/exit.c:1095
 get_signal+0x1398/0x14e0 kernel/signal.c:2933
 arch_do_signal_or_restart+0xbc/0x760 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+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f729d15cfce
RSP: 002b:00007ffe781d5778 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000555568da6500 RCX: 00007f729d15cfce
RDX: 00007ffe781d57d0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f729d417da0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000044e70
R13: 00007f729d41609c R14: 00000000000442ac R15: 00007ffe781d5900
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 f91b3f30cb7330a7f558b7a5adc554d01bdf7d6e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __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+0x2c9/0x370 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 f91b3f30cb7330a7f558b7a5adc554d01bdf7d6e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:nf_reset_trace include/linux/skbuff.h:4929 [inline]
RIP: 0010:skb_scrub_packet+0x1df/0x3d0 net/core/skbuff.c:6122
Code: 2e 01 00 00 e8 f2 6f 10 fd 49 bd 00 00 00 00 00 fc ff df 43 80 3c 2f 00 74 08 4c 89 f7 e8 19 53 68 fd 48 c7 43 68 00 00 00 00 <4c> 8d bb 81 00 00 00 4c 8d a3 84 00 00 00 4c 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc90000230088 EFLAGS: 00000246
RAX: ffffffff84772c0a RBX: ffff888161c35780 RCX: ffff888103679300
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900002300b8 R08: ffff888103679300 R09: 0000000000000002
R10: 0000000000000000 R11: ffffffff8374e7a0 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888161c357e8 R15: 1ffff1102c386afd
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562b9dfffb50 CR3: 000000010afee000 CR4: 00000000003526b0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 ____dev_forward_skb include/linux/netdevice.h:4074 [inline]
 __dev_forward_skb2+0x2c8/0x770 net/core/dev.c:2265
 __dev_forward_skb+0x26/0x40 net/core/dev.c:2277
 veth_forward_skb drivers/net/veth.c:322 [inline]
 veth_xmit+0x31c/0xb20 drivers/net/veth.c:378
 __netdev_start_xmit include/linux/netdevice.h:4975 [inline]
 netdev_start_xmit include/linux/netdevice.h:4984 [inline]
 xmit_one net/core/dev.c:3681 [inline]
 dev_hard_start_xmit+0x21b/0x760 net/core/dev.c:3697
 __dev_queue_xmit+0x1905/0x3690 net/core/dev.c:4533
 dev_queue_xmit include/linux/netdevice.h:3141 [inline]
 br_dev_queue_push_xmit+0x55c/0x700 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]
 maybe_deliver net/bridge/br_forward.c:191 [inline]
 br_flood+0x50e/0x730 net/bridge/br_forward.c:237
 br_handle_frame_finish+0x12f9/0x1760 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+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+0xd0/0x610 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+0x1aa/0x630 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xb8/0x110 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __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+0x2c9/0x370 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
 </TASK>
net_ratelimit: 106999 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:a6:18:55:90:ed:fd, 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 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)
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)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/26 16:41 android16-6.12 c69c5b7bed00 ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in wg_destruct
* Struck through repros no longer work on HEAD.