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 1BB4B3FB05A; Wed, 20 May 2026 18:05:01 +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=1779300302; cv=none; b=HRSqxTo+Q1xzbJQ+IKbaiIYy9cICJKUAwiFhgQF8nqdmWTV/aiujySrLkY4IyWor/EOFCw+v+8+tsz5vwOEYABtvYFJuE3PuxgQ6B72Nk7q58AKiG24XyEA2U773lORQ18paF6WdVdQWpeoUftZLUQwzaWrUHTQqRNz4m1M+cJE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779300302; c=relaxed/simple; bh=FFCp6D53JdbuySBbgaBvNH8LJRQzuXRJhAT3RKqnnTc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KrghvLHiyARzL+V1RHaoh976iUcdb83U35Vb3rQVdaOO87pvzJA+eSp9dKulkqK4olrAm1wUIiG/TLTZF6uB5KEtThoZUKkPLo+hZvEtbmyoBo0Wn/ndCCy87BVAYH5N1vpOdoKiDd6SX6OBxCoVi/MsIS+xLgYxysnwjLqtBNc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=E2kHAra5; 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="E2kHAra5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81FAF1F000E9; Wed, 20 May 2026 18:05:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779300301; bh=jvu8TUcAgh5seokudOG8tzppI0TQYdcC95gKPg3UVOY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=E2kHAra5lk2iPw6yM1aK0Ix7VddNU8ug6kNA1aXgmeGcBYl9mbB8E9WlQ/l+J6USG lImsOxwXoQTd5vBvhifBO+GqZyw2oIs4L4yJnI+YFbwdk03jSJEXe+Df1ARwHng6HC XCNgU25x+N/6WrOlySn0Yhfg2gTO2DL4teLhmYns= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Sasha Levin Subject: [PATCH 6.12 081/666] netfilter: nft_fwd_netdev: check ttl/hl before forwarding Date: Wed, 20 May 2026 18:14:52 +0200 Message-ID: <20260520162112.987419077@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162111.222830634@linuxfoundation.org> References: <20260520162111.222830634@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 6.12-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