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 D21B441A8F; Sat, 30 May 2026 18:36:57 +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=1780166218; cv=none; b=qoX1d/63+/EvdGgJkSu7mYycGVz2dBbFKW3RUur+yP6oQRANRxk+1bQSBr/IzqwisHRw0SP2r3kpFS4TxOKciKPezBx7MuHgs6lII9jogzNx/5hzfkyMYeH8UnDfvhEmrqM/opp9/qVtTSuWbub2vmEbGuGNJNwSWkx7EJ2L4aM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780166218; c=relaxed/simple; bh=3yUaBhzFmKRaS4XovfVQSpUCDbHLZi/F50V+LDS2HT0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rlaiiSjGYQZnfjeu2Tk33soHEQxxhwxftQukyU0qNxg2HSNRkkK+yrs2OxFaAhV2+F7BOFf1HwG24CW2mNn9xcrQ5OML4nnhxR51RVZBH/j1T2G6oIt2REl28+BybogxxqH3SOJl/GiSd0yNXAFyhzk634jS2JXa6anMx5UAY5g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aq2D1K5y; 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="aq2D1K5y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22A361F00893; Sat, 30 May 2026 18:36:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780166217; bh=pPFF9mq1y8kCNqx+gAhapINshDssy519HE0IKGCyamQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aq2D1K5yE68XOmJ0UUu+gpsMPA/L+1UPRAYxmIPfOKQkPU4KpAw0Ktv1Baez+LAXz gKHx2gQL9J2ekEUwjvaWDusuL1sX1T5nqxysMJC2VrY203AG6FF5u8XysajknFbOZM cQQHLuETN88fOS3nBUzRKRZMCbGa5uBVU+0YwnXQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Sasha Levin Subject: [PATCH 5.10 307/589] netfilter: nft_fwd_netdev: check ttl/hl before forwarding Date: Sat, 30 May 2026 18:03:08 +0200 Message-ID: <20260530160233.022783643@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160224.570625122@linuxfoundation.org> References: <20260530160224.570625122@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 5.10-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 7730409f6f091..09aff403884b5 100644 --- a/net/netfilter/nft_fwd_netdev.c +++ b/net/netfilter/nft_fwd_netdev.c @@ -113,6 +113,11 @@ 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; @@ -129,6 +134,11 @@ 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