netdev - [syzbot] [can?] INFO: task hung in cangw_pernet_exit

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Message-ID: <69446029.a70a0220.207337.00f1.GAE@google.com>
Date: Thu, 18 Dec 2025 12:12:25 -0800
From: syzbot <syzbot+6461a4c663b104fd1169@...kaller.appspotmail.com>
To: linux-can@...r.kernel.org, linux-kernel@...r.kernel.org, 
	mkl@...gutronix.de, netdev@...r.kernel.org, socketcan@...tkopp.net, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [can?] INFO: task hung in cangw_pernet_exit_batch (5)

Hello,

syzbot found the following issue on:

HEAD commit:    8f7aa3d3c732 Merge tag 'net-next-6.19' of git://git.kernel..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=175489b4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9e5198eaf003f1d1
dashboard link: https://syzkaller.appspot.com/bug?extid=6461a4c663b104fd1169
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=139e99c2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5fe312c4cf90/disk-8f7aa3d3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c7a1f54ef730/vmlinux-8f7aa3d3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/64a3779458bb/bzImage-8f7aa3d3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6461a4c663b104fd1169@...kaller.appspotmail.com

INFO: task syz.0.17:6104 blocked for more than 148 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:25440 pid:6104  tgid:6104  ppid:5956   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
 cangw_pernet_exit_batch+0x20/0x90 net/can/gw.c:1288
 ops_exit_list net/core/net_namespace.c:205 [inline]
 ops_undo_list+0x525/0x990 net/core/net_namespace.c:252


---
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