Re: [syzbot] [wireguard?] INFO: task hung in wg_netns_pre_exit (5)

[syzbot <syzbot+f2fbf7478a35a94c8b7c@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    c113d5e32678 Merge branch 'net-spacemit-a-few-error-handli..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=13a4875a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=779072223d02a312
dashboard link: https://syzkaller.appspot.com/bug?extid=f2fbf7478a35a94c8b7c
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10cf3fe6580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16b5c8ba580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a1a0aa684791/disk-c113d5e3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6d0461aed5ba/vmlinux-c113d5e3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/05b26502bb1f/bzImage-c113d5e3.xz

The issue was bisected to:

commit d4dfc5700e867b22ab94f960f9a9972696a637d5
Author: Andrii Nakryiko <andrii@kernel.org>
Date:   Tue Mar 19 23:38:49 2024 +0000

    bpf: pass whole link instead of prog when triggering raw tracepoint

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17ccbc58580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=142cbc58580000
console output: https://syzkaller.appspot.com/x/log.txt?x=102cbc58580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f2fbf7478a35a94c8b7c@syzkaller.appspotmail.com
Fixes: d4dfc5700e86 ("bpf: pass whole link instead of prog when triggering raw tracepoint")

INFO: task kworker/u8:7:1016 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7    state:D stack:25664 pid:1016  tgid:1016  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7005
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
 wg_netns_pre_exit+0x1c/0x200 drivers/net/wireguard/device.c:419
 ops_pre_exit_list net/core/net_namespace.c:161 [inline]
 ops_undo_list+0x187/0x940 net/core/net_namespace.c:234
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158


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