From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3D0E531F9AE; Wed, 20 May 2026 16:33:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779294804; cv=none; b=d+MI2r66VpMqThukvwfeDpteOLql39Dsyg62rhxCQ2DO3R/6X/n+GfzaFiox+u/j6JQ++U875ZxxbgePgvOTg/jYIE0/khDsnW1v3w4rq9eR6q1X40CbSA5NtbEEMWp/U0U43MbleEgZxk8XfsE+5ZvfVUe4H5GesbrVV5WNzQo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779294804; c=relaxed/simple; bh=8FOeMiciDDkHM/oMlL+OEKFvWXAzAoQADOv267TrkLw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sacmEt5OySxpF7T5XhrzT8F7W1lo6uoPaPpBMu3upUrzWqf2pFQXGJ61QzWMNo5xtnzsQpLFotpJFyZC70+62zkeHIBNsis5ju75dPAIWjHbkq6mpi5bB4CbZxzjSKnujG+BTyDHSNmQd/bb7GoBK3kC5fZKQwk5aTQfgJIPZ2Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BG210Vy7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BG210Vy7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2A8B1F000E9; Wed, 20 May 2026 16:33:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779294803; bh=92vqLonM1jXBsjvbAwS9oFfwNIzKeqYNGM8/tacsQFM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BG210Vy7miwITcqjkUWuoEDpFNU49OmLYFfr2ItLYh2PZ0DCHsjOSsxpm1skVZe3q gWmG7A9FOWm6uWN5xEvdGBVFz3BwOG4mVYbLPF0GGZL4xBgqDJ7GL0t5OIbqxoY++3 ORGjZJuM1xFuhsoBqBHeenKi51NeyIqU4ctIkqm0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Sasha Levin Subject: [PATCH 7.0 0179/1146] netfilter: nft_fwd_netdev: check ttl/hl before forwarding Date: Wed, 20 May 2026 18:07:09 +0200 Message-ID: <20260520162152.332128419@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162148.390695140@linuxfoundation.org> References: <20260520162148.390695140@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal [ Upstream commit 1dfd95bdf4d18d263aa8fad06bfb9f4d9c992b18 ] Drop packets if their ttl/hl is too small for forwarding. Fixes: d32de98ea70f ("netfilter: nft_fwd_netdev: allow to forward packets via neighbour layer") Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nft_fwd_netdev.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c index 152a9fb4d23af..256e832f1bb99 100644 --- a/net/netfilter/nft_fwd_netdev.c +++ b/net/netfilter/nft_fwd_netdev.c @@ -116,6 +116,11 @@ static void nft_fwd_neigh_eval(const struct nft_expr *expr, goto out; } iph = ip_hdr(skb); + if (iph->ttl <= 1) { + verdict = NF_DROP; + goto out; + } + ip_decrease_ttl(iph); neigh_table = NEIGH_ARP_TABLE; break; @@ -132,6 +137,11 @@ static void nft_fwd_neigh_eval(const struct nft_expr *expr, goto out; } ip6h = ipv6_hdr(skb); + if (ip6h->hop_limit <= 1) { + verdict = NF_DROP; + goto out; + } + ip6h->hop_limit--; neigh_table = NEIGH_ND_TABLE; break; -- 2.53.0