WARNING: suspicious RCU usage in corrupted (3)

Status: fixed on 2025/09/17 14:55
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+9767c7ed68b95cfa69e6@syzkaller.appspotmail.com
Fix commit: 7f12c3385048 net, bpf: Fix RCU usage in task_cls_state() for BPF programs
First crash: 442d, last: 379d
Cause bisection: introduced by (bisect log) :
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

Crash: WARNING: suspicious RCU usage in task_cls_state (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
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

  
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [net?] WARNING: suspicious RCU usage in corrupted (3) 1 (3) 2025/09/14 23:37
[PATCH bpf-next v1 1/2] bpf: Restrict usage scope of bpf_get_cgroup_classid 2 (2) 2025/05/29 16:46
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: suspicious RCU usage in corrupted kernel 4 syz error 1 3014d 3014d 0/29 closed as invalid on 2019/04/08 15:02
upstream WARNING: suspicious RCU usage in corrupted (2) net 4 syz, C unreliable 7 1507d 1518d 22/29 fixed on 2023/02/24 13:50
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/06/07 21:30 18m retest repro bpf-next report log
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2025/09/08 11:50 8h20m bisect fix bpf-next OK (1) job log
2025/07/26 15:19 3h19m bisect fix bpf-next OK (0) job log log
2025/06/25 00:51 4h44m bisect fix bpf-next OK (0) job log log

Sample crash report:
=============================
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,

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/24 19:56 bpf-next 079e5c56a5c4 ed351ea7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING: suspicious RCU usage in corrupted
* Struck through repros no longer work on HEAD.