syzbot


INFO: task hung in wg_destruct

Status: premoderation: reported on 2025/09/02 02:07
Reported-by: syzbot+c67d69f61e17818448d4@syzkaller.appspotmail.com
First crash: 3d12h, last: 3d12h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in wg_destruct wireguard 1 207 425d 464d 26/29 fixed on 2024/07/09 19:14
linux-6.1 INFO: task hung in wg_destruct 1 9 444d 466d 0/3 auto-obsoleted due to no activity on 2024/09/26 04:00
upstream INFO: task hung in wg_destruct (2) wireguard 1 syz done done 130 3d01h 340d 0/29 upstream: reported syz repro on 2024/09/30 04:20

Sample crash report:
INFO: task kworker/u8:1:13 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:1    state:D stack:0     pid:13    tgid:13    ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 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
 wg_destruct+0x236/0x2e0 drivers/net/wireguard/device.c:261
 netdev_run_todo+0xaf1/0xcb0 net/core/dev.c:10895
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 default_device_exit_batch+0x815/0x8a0 net/core/dev.c:12035
 ops_exit_list net/core/net_namespace.c:178 [inline]
 cleanup_net+0x731/0xc70 net/core/net_namespace.c:642
 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
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0dd0103ec329b4c3ce546fdd10bdf8515cdb9785
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11093 Comm: syz-executor Not tainted syzkaller #0 0dd0103ec329b4c3ce546fdd10bdf8515cdb9785
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:update_stack_state+0x123/0x4b0 arch/x86/kernel/unwind_frame.c:-1
Code: ff ff 48 8d 53 18 48 8d 43 28 48 8d 73 20 48 89 b5 60 ff ff ff 4c 89 f6 48 c1 ee 03 48 89 b5 40 ff ff ff 48 89 8d 70 ff ff ff <48> c1 e9 03 48 89 8d 48 ff ff ff 48 89 95 58 ff ff ff 48 c1 ea 03
RSP: 0018:ffffc9000022fcd8 EFLAGS: 00000a06
RAX: ffffc9000022fe50 RBX: ffffc9000022fe28 RCX: ffffc9000022fe38
RDX: ffffc9000022fe40 RSI: 1ffff92000045fc6 RDI: ffffc9000022fe80
RBP: ffffc9000022fd98 R08: ffffc9000022fef0 R09: ffffc9000022fee8
R10: 0000000000000017 R11: ffffffff817441e0 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc9000022fe30 R15: ffffc9000f1972b8
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c7048dbb90 CR3: 000000010b720000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 unwind_next_frame+0x3c2/0x750 arch/x86/kernel/unwind_frame.c:315
 arch_stack_walk+0x139/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:48
 __kasan_record_aux_stack+0xb2/0xd0 mm/kasan/generic.c:541
 kasan_record_aux_stack_noalloc+0xf/0x20 mm/kasan/generic.c:551
 __call_rcu_common+0xd5/0x700 kernel/rcu/tree.c:3098
 call_rcu_hurry+0xf/0x30 kernel/rcu/tree.c:3149
 dst_release+0x1a3/0x240 net/core/dst.c:177
 refdst_drop include/net/dst.h:263 [inline]
 skb_dst_drop include/net/dst.h:275 [inline]
 skb_release_head_state+0x74/0x260 net/core/skbuff.c:1172
 skb_release_all net/core/skbuff.c:1186 [inline]
 __kfree_skb+0x29/0x210 net/core/skbuff.c:1202
 consume_skb+0x65/0x1a0 net/core/skbuff.c:1434
 arp_process+0xd79/0x1740 net/ipv4/arp.c:941
 NF_HOOK+0x154/0x1b0 include/linux/netfilter.h:317
 arp_rcv+0x2f8/0x490 net/ipv4/arp.c:991
 __netif_receive_skb_one_core net/core/dev.c:5757 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 netif_receive_skb_internal net/core/dev.c:5956 [inline]
 netif_receive_skb+0x22d/0x7b0 net/core/dev.c:6015
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_pass_frame_up+0x126/0x1c0 net/bridge/br_input.c:70
 br_handle_frame_finish+0x12d9/0x1720 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+0xf48/0x3940 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+0xd0/0x610 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
 </IRQ>
 <TASK>
 __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]
 addrconf_ifdown+0x608/0x1940 net/ipv6/addrconf.c:3951
 addrconf_notify+0x17a/0xea0 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x10e/0x2c0 kernel/notifier.c:93
 raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
 call_netdevice_notifiers_info net/core/dev.c:2067 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2105 [inline]
 call_netdevice_notifiers net/core/dev.c:2119 [inline]
 dev_close_many+0x33a/0x4f0 net/core/dev.c:1660
 unregister_netdevice_many_notify+0x4bb/0x1bd0 net/core/dev.c:11463
 unregister_netdevice_many net/core/dev.c:11551 [inline]
 unregister_netdevice_queue+0x339/0x380 net/core/dev.c:11425
 unregister_netdevice include/linux/netdevice.h:3165 [inline]
 __tun_detach+0xca1/0x1460 drivers/net/tun.c:685
 tun_detach drivers/net/tun.c:701 [inline]
 tun_chr_close+0x93/0x150 drivers/net/tun.c:3517
 __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: 0033:0x7f5c82590a23
Code: Unable to access opcode bytes at 0x7f5c825909f9.
RSP: 002b:00007fff6f818c58 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000020 RBX: 00007f5c832f4620 RCX: 00007f5c82590a23
RDX: 0000000000000020 RSI: 00007f5c832f4670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fff6f818c74 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f5c832f4670 R15: 0000000000000000
 </TASK>
net_ratelimit: 108260 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 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 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 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:9e:59:8d:67:4a:16, vlan:0)
net_ratelimit: 117617 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 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: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 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 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)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/02 02:06 android16-6.12 2e5a4bace74a 807a3b61 .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.