From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f70.google.com (mail-oo1-f70.google.com [209.85.161.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F66143F8B8 for ; Mon, 14 Sep 2026 11:53:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789386836; cv=none; b=AOENgYOhrrHMHYeKJNmA2/Vj7C0pGe0stuZ4DbasRCRopnC6qrzZuVq/NJj4gV6XOCNWqrbsiOKO5+NITq7N2PUasUKYP62bk4B2P2YwAnYCguJYMoI+PA7VY4/wHU0MTqG4wyhXmyAPumx0Xr+G9/3Jd7+cv1Tt+1pHU7+16Ak= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789386836; c=relaxed/simple; bh=Oy9g0Rm6pD4S64HJdm3CjnBlSj9nP4TkYubvGXXUt20=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=b4nF4g/SiGFWNIdjTSzpGednHtkUNRZC4t0XxIzACxoEu/unUFZxy9mzRDjgDMSPo6L+/kAKNWy4tZuqEfsbpLIOjwHJ0X+jvczXT2EZvVU74Y6lo1/CZeblEVjTt7Sp/oL6LZyPsD2W/PDEY66wR3lsowy+s8sCE4fXXvO0if0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f70.google.com with SMTP id 006d021491bc7-6c34cd4bffbso851341eaf.0 for ; Mon, 14 Sep 2026 04:53:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789386833; x=1789991633; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=3wo7UwFKH7eZA0tNkfsZQYrFComugpOZXW7NZrfaLKg=; b=rTPqzPMsvy58E3Cc3g4Upp1Xbsj5OibqfWbT/m6JAf2CKAMxEGFtYW5+EDfgAqgBed 7ke9NSJ0sPXfNRN3i+VXhN+CsyS32zICmBU6FseVWkMl/ib7+HPA9yX/u309F3za6F4Z zMPmzI21HC2oO1hxbhTdIvKZtLXGltkL7ZA3NbzBaWJnhunXIvPVmbjZbfF3bxvUe+zx 1aIPv0efFV4kh+WGu0uLVc76wCfM+UIGQpiaECEJbedUblVeeS3g1PY6UCDCapFj0FWd t7RqmHAyKWPs8gBsOImhYAzuhvfdSG5gQqK1NoArTLWYnMkXVF5pp/YOcackDUyF8wya BRcA== X-Gm-Message-State: AFuF++nd5J8AdNAhXrPgcubMoj+Qz8U9ulNvrOf901zqLnuf7Th6oXsr GdyVBDV+RQY2xjNT2zveRgtSbG5u1qlhUc4QLQUFUHvoKwW/zyOgu1WDpxYb8TD+ZUSx1If1m9w fI/4jR68SbuQOelQeStGf9y9i6EwdgFVrI5cBRqUIDgEqHN8qjBfcQW1E4Og= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:3091:b0:6b7:8396:f3d4 with SMTP id 006d021491bc7-6c541d435aemr900088eaf.54.1789386833520; Mon, 14 Sep 2026 04:53:53 -0700 (PDT) Date: Mon, 14 Sep 2026 04:53:53 -0700 In-Reply-To: <6aa4a377.f81106d8.2ab401.0024.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aa7e051.016ef6ab.da411.001e.GAE@google.com> Subject: Forwarded: [PATCH] WARNING: suspicious RCU usage in expect_iter_name From: syzbot To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org. *** Subject: [PATCH] WARNING: suspicious RCU usage in expect_iter_name Author: jchuang26@m.fudan.edu.cn #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git 15071f2a1263e82150c77eeb1e94dbfc31950a8e Reported-by: syzbot+4bd730aede2791e40bdf@syzkaller.appspotmail.com diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 9b4e29557..2449df2e9 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -3390,7 +3390,13 @@ static bool expect_iter_name(struct nf_conntrack_expect *exp, void *data) struct nf_conntrack_helper *helper; const char *name = data; - helper = rcu_dereference(exp->helper); + /* This iterator runs under nf_conntrack_expect_lock (see + * nf_ct_expect_iterate_net()), which serializes changes to exp->helper. + * Use the protected accessor to document that lock-based protection and + * avoid a bogus RCU lockdep splat. + */ + helper = rcu_dereference_protected(exp->helper, + lockdep_is_held(&nf_conntrack_expect_lock)); if (!helper) return false;