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 E2E6822D7B9; Thu, 2 Jul 2026 16:53:53 +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=1783011235; cv=none; b=ucJcM+BSduD4IcCOs5XohqxXDk8Cs/ltO9G4qpt+rUPpII4caob+q9RljlRtLxc/9Nr+LEGCSYhvgJiL7vZj0Ts0vZZfWHnk6qStSvsjJw6gVlm5ViZTiWVtmQ2PVhMY/9gFlRR7/JOjHVXTSl+asfnOGxfHwcXM90A/aRnImxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783011235; c=relaxed/simple; bh=hGMqQVzxXkGI11O3QyDp//6LwvqBdC4h6wxQbPUV4Yg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gh+DFKrdUG7Z6nB4cdLeMPofmLcEEqh1UqGJ+lI+ZzlGF884zyCW/vBbRsx36af9mQBlQSeN5PK4KlIlRBELBQTt1Z/sU1IwHKdzyojaaCRtjjaPulj0g/GzSTpp3UGi1qzs/o9xqNH5+dVRTU9ltAw6SCZxfew79rj2VfLfKDk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Png7T0La; 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="Png7T0La" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5498C1F000E9; Thu, 2 Jul 2026 16:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783011233; bh=oy5M84J4VyuTxRchTgEs+Vx5Y2oC0pxmCax4oejt4g8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Png7T0LaQbeXDvsLzi8vxejMzKQwLhXT5yWCefQNTgHWpp9cvUcpYidn63YChTSpr Blt6wXFYRPe8MGjGi4d/lVthCai9jSXYD5wH7GSE1AJvEGCNW2i4hhrBDIlkJXfbq5 l3RtjMIioRqLbT8ZQt6yOSZExWE6jly7GWFstGA0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Sven Eckelmann , Sasha Levin Subject: [PATCH 6.18 030/108] batman-adv: tvlv: enforce 2-byte alignment Date: Thu, 2 Jul 2026 18:20:27 +0200 Message-ID: <20260702155112.735309679@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155112.110058792@linuxfoundation.org> References: <20260702155112.110058792@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 32a6799255525d6ea4da0f7e9e0e521ad9560a46 upstream. The fields of an aggregated OGM(v2) are accessed assuming (at least) 2-byte alignment, so a following OGM must start at an even offset. As the header length is even, an odd tvlv_len would misalign it and trigger unaligned accesses on strict-alignment architectures. Such a misaligned TVLV/OGM/OGMv2 is not created by a normal participant in the mesh. Therefore, reject such malformed packets. Cc: stable@kernel.org Fixes: ef26157747d4 ("batman-adv: tvlv - basic infrastructure") Signed-off-by: Sven Eckelmann Signed-off-by: Sasha Levin --- net/batman-adv/bat_iv_ogm.c | 11 ++++++++++- net/batman-adv/bat_v_ogm.c | 11 ++++++++++- net/batman-adv/routing.c | 6 ++++++ net/batman-adv/tvlv.c | 6 ++++++ 4 files changed, 32 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index b8b1b997960a96..6e79f69c2fedec 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -311,14 +311,23 @@ batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len, const struct batadv_ogm_packet *ogm_packet) { int next_buff_pos = 0; + u16 tvlv_len; /* check if there is enough space for the header */ next_buff_pos += buff_pos + sizeof(*ogm_packet); if (next_buff_pos > packet_len) return false; + tvlv_len = ntohs(ogm_packet->tvlv_len); + + /* the fields of an aggregated OGM are accessed assuming (at least) + * 2-byte alignment, so a following OGM must start at an even offset. + */ + if (tvlv_len & 1) + return false; + /* check if there is enough space for the optional TVLV */ - next_buff_pos += ntohs(ogm_packet->tvlv_len); + next_buff_pos += tvlv_len; return next_buff_pos <= packet_len; } diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 6852bf5da8c558..1f9b2d2b4831ce 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -849,14 +849,23 @@ batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, const struct batadv_ogm2_packet *ogm2_packet) { int next_buff_pos = 0; + u16 tvlv_len; /* check if there is enough space for the header */ next_buff_pos += buff_pos + sizeof(*ogm2_packet); if (next_buff_pos > packet_len) return false; + tvlv_len = ntohs(ogm2_packet->tvlv_len); + + /* the fields of an aggregated OGMv2 are accessed assuming (at least) + * 2-byte alignment, so a following OGMv2 must start at an even offset. + */ + if (tvlv_len & 1) + return false; + /* check if there is enough space for the optional TVLV */ - next_buff_pos += ntohs(ogm2_packet->tvlv_len); + next_buff_pos += tvlv_len; return next_buff_pos <= packet_len; } diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 4483f8d9c75831..41951c7a1c50b2 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -1366,6 +1366,12 @@ int batadv_recv_mcast_packet(struct sk_buff *skb, if (tvlv_buff_len > skb->len - hdr_size) goto free_skb; + /* the fields of an multicast payload are accessed assuming (at least) + * 2-byte alignment, so a following packet must start at an even offset. + */ + if (tvlv_buff_len & 1) + goto free_skb; + ret = batadv_tvlv_containers_process(bat_priv, BATADV_MCAST, NULL, skb, tvlv_buff, tvlv_buff_len); if (ret >= 0) { diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c index cde798c82dcf13..63fb54024d1543 100644 --- a/net/batman-adv/tvlv.c +++ b/net/batman-adv/tvlv.c @@ -464,6 +464,12 @@ int batadv_tvlv_containers_process(struct batadv_priv *bat_priv, if (tvlv_value_cont_len > tvlv_value_len) break; + /* the next tvlv header is accessed assuming (at least) 2-byte + * alignment, so it must start at an even offset. + */ + if (tvlv_value_cont_len & 1) + break; + tvlv_handler = batadv_tvlv_handler_get(bat_priv, tvlv_hdr->type, tvlv_hdr->version); -- 2.53.0