From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dvalin.narfation.org (dvalin.narfation.org [213.160.73.56]) (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 49D8F318BA6 for ; Fri, 29 May 2026 18:13:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.160.73.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780078420; cv=none; b=gOhXdxsj4NzfMHeMbA2h3YqOhOjXSe/u/B0bBG81DU/5zUn8401mPquJPUmWWSyXhZvxysMbvmYf+EIosSzlwkkAyACyeWneGZqu6B+DCaEfmKRelyG6Zl3u1iLPzYWJTvc+pnzar8M68Ed9RYc/HP69DwsDPc0JKnV4gaHRK/s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780078420; c=relaxed/simple; bh=G/+2fixiTy7Khx7ht17iUzCRz5GzbzzwuzdhuTpaXUk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RDbXkXpwvJQkaEcLpblk/bVQ/Ktgdz/aJD8o3J4do9YDR+pnGs9YAUIofLR+rJgVCtpiIlBcGfXR5h+QXDo83HFZK36UklHwqFmi6FkZKn+k26dsFMPmunNEd6vf+gRFJZubeEuu9vDwpwNJvwI9lBAcYjHdkrONEVQc45cN668= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org; spf=pass smtp.mailfrom=narfation.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b=I3ao4+au; arc=none smtp.client-ip=213.160.73.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=narfation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b="I3ao4+au" Received: by dvalin.narfation.org (Postfix) id 6D8FE2000E; Fri, 29 May 2026 18:13:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1780078417; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jcZEoLYO2P1d4iv6aORorNT6QhHUtis/MDa9co2z+n0=; b=I3ao4+auY0JZRJyRW4ijB3ZLNn8O/FboLtUrn6YrCH7fiZThDcmEbDNrXeD3VhIifStweh aW4fHOZPMZqn1Yu1aIg0HpZehKTEY+/cPfLsTJPdsWqOZDbRSPamDpn5Ze6JT52eJbj5Y7 2ccuNSLZMcoHQHg/BaDXHvUrEFHqYpk= From: Sven Eckelmann To: stable@vger.kernel.org Cc: Sven Eckelmann , stable@kernel.org Subject: [PATCH 6.6.y] batman-adv: tt: reject oversized local TVLV buffers Date: Fri, 29 May 2026 20:13:27 +0200 Message-ID: <20260529181328.416135-1-sven@narfation.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <2026052827-sanctity-identical-24ce@gregkh> References: <2026052827-sanctity-identical-24ce@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit commit 1e9fab756f8395096d5bba7be0c373c4c8f5d165 upstream. The commit 3a359bf5c61d ("batman-adv: reject oversized global TT response buffers") added a check to ensure that a global return buffer size can be stored in an u16. The same buffer handling also exists for the local data buffer but was not touched. A similar check should be also be in place for the local TVLV buffer. It doesn't have the similar attack surface because it is only generated from locally discovered MAC addresses but the dynamic nature could still cause temporarily to large buffers. Cc: stable@kernel.org Fixes: 7ea7b4a14275 ("batman-adv: make the TT CRC logic VLAN specific") [ Context ] Signed-off-by: Sven Eckelmann --- net/batman-adv/translation-table.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index d830ccf016697..8ffebece03c52 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -924,12 +924,12 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, { struct batadv_tvlv_tt_vlan_data *tt_vlan; struct batadv_softif_vlan *vlan; + size_t change_offset; u16 num_vlan = 0; u16 vlan_entries = 0; u16 total_entries = 0; u16 tvlv_len; u8 *tt_change_ptr; - int change_offset; spin_lock_bh(&bat_priv->softif_vlan_list_lock); hlist_for_each_entry(vlan, &bat_priv->softif_vlan_list, list) { @@ -948,8 +948,10 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, if (*tt_len < 0) *tt_len = batadv_tt_len(total_entries); - tvlv_len = *tt_len; - tvlv_len += change_offset; + if (check_add_overflow(*tt_len, change_offset, &tvlv_len)) { + tvlv_len = 0; + goto out; + } *tt_data = kmalloc(tvlv_len, GFP_ATOMIC); if (!*tt_data) { -- 2.47.3