syzbot


INFO: task hung in setup_net

Status: premoderation: reported on 2026/01/31 18:04
Reported-by: syzbot+c135381202ba6ab361f4@syzkaller.appspotmail.com
First crash: 2d05h, last: 2d05h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in setup_net net 1 19 222d 603d 0/29 auto-obsoleted due to no activity on 2025/09/23 22:48

Sample crash report:
INFO: task syz.0.608:2180 blocked for more than 125 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.608       state:D stack:0     pid:2180  tgid:2179  ppid:290    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_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
 setup_net+0x8e8/0x9b0 net/core/net_namespace.c:394
 copy_net_ns+0x512/0xa30 net/core/net_namespace.c:510
 create_new_namespaces+0x3b5/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x502/0x880 kernel/fork.c:3356
 __do_sys_unshare kernel/fork.c:3427 [inline]
 __se_sys_unshare kernel/fork.c:3425 [inline]
 __x64_sys_unshare+0x3c/0x50 kernel/fork.c:3425
 x64_sys_call+0x2998/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:273
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f68f539aeb9
RSP: 002b:00007f68f3df7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f68f5615fa0 RCX: 00007f68f539aeb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007f68f5408c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68f5616038 R14: 00007f68f5615fa0 R15: 00007ffc6801e1e8
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 001c7e68fa735976e9f6b7ad125989e1d2b10b0e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 406 Comm: kworker/0:4 Not tainted syzkaller #0 001c7e68fa735976e9f6b7ad125989e1d2b10b0e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-crypt-wg1 wg_packet_decrypt_worker
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 97 05 48 89 de e8 b0 b9 53 00 5b 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc b8 dd 26 d0 38 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 48 8b 45 08 65 48 8b 0d 1c 4e 7d 7e 65 8b
RSP: 0018:ffffc90000007480 EFLAGS: 00000202
RAX: ffffffff84f11a42 RBX: ffff888116989000 RCX: 0000000000000100
RDX: ffff8881160a8000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: ffffc90000007530 R08: ffff88811698903f R09: 0000000000000000
R10: ffff888116989028 R11: ffffed1022d31208 R12: 0000000000000002
R13: ffff888103b58258 R14: 0000000000000002 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007eff01a04f0e CR3: 0000000156730000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 ipv6_rcv+0xd2/0x240 net/ipv6/ip6_input.c:306
 __netif_receive_skb_one_core net/core/dev.c:5763 [inline]
 __netif_receive_skb net/core/dev.c:5876 [inline]
 netif_receive_skb_internal net/core/dev.c:5962 [inline]
 netif_receive_skb+0x147/0x7b0 net/core/dev.c:6021
 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:5657
 __netif_receive_skb_one_core net/core/dev.c:5761 [inline]
 __netif_receive_skb net/core/dev.c:5876 [inline]
 process_backlog+0x3e5/0xad0 net/core/dev.c:6212
 __napi_poll+0xd3/0x610 net/core/dev.c:6863
 napi_poll net/core/dev.c:6932 [inline]
 net_rx_action+0x5ea/0xd80 net/core/dev.c:7054
 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
 __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]
 ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
 wg_packet_decrypt_worker+0x2b6/0xd50 drivers/net/wireguard/receive.c:499
 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+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 120526 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:ae:66:40:00:a2:10, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:ae:66:40:00:a2:10, 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:ae:66:40:00:a2:10, 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:ae:66:40:00:a2:10, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:ae:66:40:00:a2:10, 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:ae:66:40:00:a2:10, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/31 18:03 android16-6.12 c13babfee861 afc0c4d4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in setup_net
* Struck through repros no longer work on HEAD.