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 9D7CB342509; Thu, 2 Jul 2026 16:33:18 +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=1783009999; cv=none; b=dx6BQTUONR7TwBP6//kMMuK0Rd+eum7yXv/eokIntDVHbGLSgONyIegN3o9JfcKSNeQB/pGYWCAop3q6Bfmol9k/azUnhOxmNxPcSKF+r0I2ncrdq2xkq4LgEW/hjQ8CoR63vn5rvo9YkRbA4uRxsDDblR8ZjyR6C1G6iz/TMlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783009999; c=relaxed/simple; bh=SUvYI1SI1ISsCxmcZgaU2/5VbdT/6+KqPvpxssj0OSk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PUGF59SSGRNTvmPe9B3g0Dz28C78R57WkR57oMbsAo+WEvyagreN+STMotn/Zb2DTP9U1eTH8z2MVgVrxBk8ILyJASPZ1gvZOTq38HQTnoJp14KItEpCyLQYSDF30SNBCn8f+smtsysJFtRt7x+sipunQJtY43rDzxn4CKzBrFo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yCIaXEWF; 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="yCIaXEWF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 102591F000E9; Thu, 2 Jul 2026 16:33:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783009998; bh=ntmr+yrrA6KazHAjkabkvcS1mKxTvQxU/kEdX00+cA0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=yCIaXEWFhQieNOJBH6OJ//oBr70qmUyeonHQMVrdIoJQbo+XuXMNLALy9OvKNCDvy 8g7T2PxS3UtR3eBl8fV+Nr1iuXpZClgQJiLkOoxOJoMqvSkKHpN0DnUA8vlPYoiyU7 CkdR//5BVNkmiSmQHzN8KpSIVqxbvAqLhtL2Q84M= 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 6.1 073/129] batman-adv: tvlv: enforce 2-byte alignment Date: Thu, 2 Jul 2026 18:19:52 +0200 Message-ID: <20260702155113.654542289@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155112.163984240@linuxfoundation.org> References: <20260702155112.163984240@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 6.1-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") [ Drop change for non-existing mcast handling ] 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/tvlv.c | 6 ++++++ 3 files changed, 26 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index c52e3b82889868..7fd692b642e392 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 f87c2b80e4291e..e8ad4817d20018 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -854,14 +854,23 @@ 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/tvlv.c b/net/batman-adv/tvlv.c index 99e5e8518dcc9a..e25430da5afb1b 100644 --- a/net/batman-adv/tvlv.c +++ b/net/batman-adv/tvlv.c @@ -448,6 +448,12 @@ 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