From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 622078462 for ; Mon, 25 May 2026 17:53:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779731626; cv=none; b=nHC5jtfyHNsFsjcT6NOKP4v/UNse6WQ18vDVIq1M5oFkUr0GTuXfiSVQfltOdgpCtvm5mf3i16gsjTTYAGiFlB7gxcO382q8CUqBWZ/2oTw7WpOqrfjUDPbhWi4TxRGWA7cf1XG87E1RDQ8wWYlB+m5EhBl3W5SjBKP5y2CsVeE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779731626; c=relaxed/simple; bh=eGZGnF1/vH/i8T6SXiT16xpmMF9oB/vu5Ss2uA3zkIk=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=HoF+Dt4HbPHy489eAEg34B10r91w2+5qjBuS5vsoFtvVyT0kMjbgLoCEcg/E+WOmvfchwPjlkXNJeUsYzadFSmGtjDXUJ1uiuYFQQky9g8+XSh4Ukk8YDyCBidBYe50jlA3anPyQrxSzoJwucGEBGUMjBl9qBJOolU9M41dC4dk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=strlen.de; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=strlen.de Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003) id 9677260595; Mon, 25 May 2026 19:53:35 +0200 (CEST) Date: Mon, 25 May 2026 19:53:35 +0200 From: Florian Westphal To: Jiayuan Chen Cc: netfilter-devel@vger.kernel.org Subject: Followup needed for netfilter: nft_fib_ipv6: walk fib6_siblings under RCU? Message-ID: Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hello, Sashiko claims we need this change: diff --git a/net/ipv6/netfilter/nft_fib_ipv6.c b/net/ipv6/netfilter/nft_fib_ipv6.c --- a/net/ipv6/netfilter/nft_fib_ipv6.c +++ b/net/ipv6/netfilter/nft_fib_ipv6.c @@ -191,6 +191,9 @@ static bool nft_fib6_info_nh_uses_dev(struct fib6_info *rt, if (nft_fib6_info_nh_dev_match(nh_dev, dev)) return true; + + if (!READ_ONCE(rt->fib6_nsiblings)) + return false; } return false; Could ypu please check and send a followup if its correct? AFAICS the nodes can be relinked to a *different* list and then this turns into busyloop without the extra test. https://sashiko.dev/#/patchset/20260520023411.391233-1-jiayuan.chen%40linux.dev Thank you.