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 C6210315D33; Thu, 2 Jul 2026 16:41:09 +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=1783010470; cv=none; b=m92Na6iZCIrexVTtUAi99DH478HrAjHWHuAmk5Ni1b53bogynHhVd7uVxNG2fXEuCs6Refm2C6fvpE9tiBqnKtuOlNJ+1B6q8NgrNbDE+kyqDftaGQBhwQ1Hj3tr6WCGEJK9y5geQItvBqDTNj5YHKXyPTVq34GjZMfjSo3xyL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010470; c=relaxed/simple; bh=lAHeCnbPch4JmCgg53IzBk6H1Xn4qbpwu+loCNrDGiE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WM3azi46uGwMPUgRvUZ50GhMvTCZIeV1u2kgF6LVdJff2/EZbjn3fK9EGgWidoJ2axWd+7+CA4ihIJyeIRpdPcSAIFAclkVI+NNmGKGRXT6NhdVNl3IAjg8UnSFOTJFteWSvaH+S/DPxFVwyq7k6qQUOnyAIkZuQk1Yd5eGEJ9g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mIVMGgmR; 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="mIVMGgmR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D14C31F000E9; Thu, 2 Jul 2026 16:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783010469; bh=HXJeOBd5gWk+bOS2mIRFCPEYh7xLBMZPw+hxhV97Q54=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mIVMGgmRt2pH+Eey3l31kkfD8Ga2sr5566AtEWAt+8J9Ox0h/Z+28NYSMpaJYHGCj JWp+QJc+jJx1Gc64ahgWjMkWjNtBOAHfIqk74kmKAnRIZzObG4apV2FZdl/p1yfJ4H +qxT27gRZS7jL+FgH4ML6LkFgJ49DoYiOCkOCA8o= 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 6.12 122/204] batman-adv: tvlv: enforce 2-byte alignment Date: Thu, 2 Jul 2026 18:19:39 +0200 Message-ID: <20260702155121.215585795@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155118.667618796@linuxfoundation.org> References: <20260702155118.667618796@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: 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 b37c9fb178ae50..5dd3e1f281bab2 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -310,14 +310,23 @@ 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 48a67705eba85c..c5c4d33cb19838 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -853,14 +853,23 @@ 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 6fd18b69e5f6be..f828d8143f7526 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -1373,6 +1373,12 @@ 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 8d6b017c433cc9..e1cd27b99bd119 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