[syzbot] [net?] WARNING: suspicious RCU usage in corrupted (3)

[syzbot] [net?] WARNING: suspicious RCU usage in corrupted (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    079e5c56a5c4 bpf: Fix error return value in bpf_copy_from_..
git tree:       bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12739ad4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c6c517d2f439239
dashboard link: https://syzkaller.appspot.com/bug?extid=9767c7ed68b95cfa69e6
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=114915f4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15566170580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8d7d35d067bc/disk-079e5c56.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/74d2648ea7f4/vmlinux-079e5c56.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e751e253ee4f/bzImage-079e5c56.xz

The issue was bisected to:

commit ee971630f20fd421fffcdc4543731ebcb54ed6d0
Author: Feng Yang <yangfeng@kylinos.cn>
Date:   Tue May 6 06:14:33 2025 +0000

    bpf: Allow some trace helpers for all prog types

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=130ddad4580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=108ddad4580000
console output: https://syzkaller.appspot.com/x/log.txt?x=170ddad4580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9767c7ed68b95cfa69e6@syzkaller.appspotmail.com
Fixes: ee971630f20f ("bpf: Allow some trace helpers for all prog types")

=============================
WARNING: suspicious RCU usage
6.15.0-rc4-syzkaller-g079e5c56a5c4 #0 Not tainted
-----------------------------
net/core/netclassid_cgroup.c:24 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, 


---
This report is generated by a bot. It may contain errors.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

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Re: [syzbot] [net?] WARNING: suspicious RCU usage in corrupted (3)

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 7f12c33850482521c961c5c15a50ebe9b9a88d1e
Author: Charalampos Mitrodimas <charmitro@posteo.net>
Date:   Wed Jun 11 17:20:43 2025 +0000

    net, bpf: Fix RCU usage in task_cls_state() for BPF programs

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=13745562580000
start commit:   079e5c56a5c4 bpf: Fix error return value in bpf_copy_from_..
git tree:       bpf-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=c6c517d2f439239
dashboard link: https://syzkaller.appspot.com/bug?extid=9767c7ed68b95cfa69e6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=114915f4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15566170580000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: net, bpf: Fix RCU usage in task_cls_state() for BPF programs

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [net?] WARNING: suspicious RCU usage in corrupted (3)

[Charalampos Mitrodimas]

syzbot <syzbot+9767c7ed68b95cfa69e6@syzkaller.appspotmail.com> writes:

> syzbot suspects this issue was fixed by commit:
>
> commit 7f12c33850482521c961c5c15a50ebe9b9a88d1e
> Author: Charalampos Mitrodimas <charmitro@posteo.net>
> Date:   Wed Jun 11 17:20:43 2025 +0000
>
>     net, bpf: Fix RCU usage in task_cls_state() for BPF programs
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=13745562580000
> start commit:   079e5c56a5c4 bpf: Fix error return value in bpf_copy_from_..
> git tree:       bpf-next
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c6c517d2f439239
> dashboard link: https://syzkaller.appspot.com/bug?extid=9767c7ed68b95cfa69e6
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=114915f4580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15566170580000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: net, bpf: Fix RCU usage in task_cls_state() for BPF programs

Correct, also did test-run to make sure.

#syz fix: net, bpf: Fix RCU usage in task_cls_state() for BPF programs

C. Mitrodimas

>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection