syzbot


INFO: task hung in fib_net_exit_batch (3)

Status: auto-obsoleted due to no activity on 2026/03/10 22:11
Subsystems: net
[Documentation on labels]
First crash: 99d, last: 99d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in fib_net_exit_batch 1 6 640d 653d 0/3 auto-obsoleted due to no activity on 2024/09/25 07:15
upstream INFO: task hung in fib_net_exit_batch net 1 2 1357d 1360d 0/29 auto-closed as invalid on 2022/09/29 00:33
upstream INFO: task hung in fib_net_exit_batch (2) net 1 19 386d 663d 0/29 auto-obsoleted due to no activity on 2025/05/27 12:53

Sample crash report:
INFO: task syz-executor:11491 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23560 pid:11491 tgid:11491 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 fib_net_exit_batch+0x22/0xf0 net/ipv4/fib_frontend.c:1676
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x525/0x990 net/core/net_namespace.c:252
 setup_net+0x2e8/0x330 net/core/net_namespace.c:462
 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226
 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3128
 __do_sys_unshare kernel/fork.c:3199 [inline]
 __se_sys_unshare kernel/fork.c:3197 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3197
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/10 22:08 net-next 8f7aa3d3c732 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in fib_net_exit_batch
* Struck through repros no longer work on HEAD.