[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 <yang...@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+9767c7...@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,


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[syzbot]

syzbot suspects this issue was fixed by commit:

commit 7f12c33850482521c961c5c15a50ebe9b9a88d1e
Author: Charalampos Mitrodimas <char...@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

[Charalampos Mitrodimas]

Correct, also did test-run to make sure.

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

C. Mitrodimas