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 5632038B149 for ; Tue, 15 Sep 2026 01:38:41 +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=1789436327; cv=none; b=tHh8jXu73Q9OE4rkJNYon8mFngYMrUmdHUUfvmDaRqwzwtJI2Dq1rOnDcUyJUpCZDIBkostjhHvnx86XesJvUKaiItGTC73QM8NF9M5OrdGbVEif1EmprLIBLbzBOUGCSP3kcH5a8qLYtWeZNfbEhOvGzKOYbVmJ+q959FLQPL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789436327; c=relaxed/simple; bh=/TKrTZgd0YfyEjb54nAEPi+Q7v30e2+bVMpdLEFoDlw=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=U085zKlEoARC+uq8s0cHoCXURqVWiIX7zO5JTs27Mpw+/hicaoh2YhOXnqgEqA22aymUhwvECuSra99aRwou+DAtJJrEYdrb+b/79znkZx90DyceZEfuAN//40Jrd4y92aojLtYgwdY4Asr109NoXLz2uCLp8RSR6bGbsdgSAxs= 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 006d021491bc7-6c2bb8200b0so3511659eaf.1 for ; Mon, 14 Sep 2026 18:38:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789436321; x=1790041121; 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=hgg7l0OlgFO6mh/Pim1q7cd/wJ4O30YZyz+wzdxOAHc=; b=XkNDs6+0uy+0Hsw7Ia5GNq3F9k8USnkjrMdWlNDx9Vk6QFyJZfdsH4wcK8WuCDS/UU 8TPlOm1cqr5Z/RSDQXTbVLIBDC8F00YrOMEcUbhYQo61S04IDpr+ekTgqB1dqYlc3tuj HzNot8ujNqR67mZstETHLX2AWuuVHrm41D2d9FflGvtwINGQRf4Fd8qB5Qjs2H+txgs3 PQixm5v9oSgCwAKryfNQ00C9jVwdxUldN67FcsiIyj7TuJlbgfwXkJkLNTUwFHAjQG4d hx0Vn8DR8Ccxu7V2yQmsvxceuMPo1TxfyVaVaUwBpkuy5F9g3DkAoUm2tDDcWXFXoq2Q YYMQ== X-Gm-Message-State: AFuF++nyZCoG0pbFipvqwmUc0fvD4leUrJ9Xo/kqVE3Uf3VwD/swzpen /4GZ/NMMrZdotc/LRLcFwTLKul43FsbSbT7FE8Ep4YkZt65jG9wW16HjMqL4flXfWVJdEbh9HBL 0LJb7zlcGFiY3gqI2ZkxJll6QIUh1CoA9RWf2BmTd/8qKHOVHE8+k53Vt89M= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:16a3:b0:6b1:8780:70fe with SMTP id 006d021491bc7-6c54214a0bbmr2931611eaf.2.1789436320949; Mon, 14 Sep 2026 18:38:40 -0700 (PDT) Date: Mon, 14 Sep 2026 18:38:40 -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: <6aa8a1a0.a211d2ce.1a5198.02a0.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 master 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;