[syzbot] [can?] INFO: task hung in cangw_pernet_exit_batch (5)

[syzbot] [can?] INFO: task hung in cangw_pernet_exit_batch (5)

[syzbot]

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@syzkaller.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


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [can?] INFO: task hung in cangw_pernet_exit_batch (5)

[Oliver Hartkopp]

Hi all,

the syslog for this issue is full of bluetooth error messages that could 
be related to this recently reverted patch:

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git/commit/?id=252714f1e8bdd542025b16321c790458014d6880

Therefore I assume the problem not to be related to the CAN subsystem.
Let's see if after the bluetooth fix another syzbot splat shows up.

Best regards,
Oliver

On 18.12.25 21:12, syzbot wrote:
> 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@syzkaller.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
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup
>