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 44C533AE185 for ; Fri, 29 May 2026 20:04:53 +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=1780085094; cv=none; b=qyBn4ndRs04uWDDBOg1EiTD0IAiTxkv5gAGodqb/rOZ0vRl1D/yJRaR7IUUxShD9lRtDjxKwe6KY4vlH26c0vFQBHM5syFJgli+e6x9u4WpvZVPCcQKNbQCmOFIzKwLF3Thy2f7k3FSLuIQw4KCU+V6gVLB5+JbOdUDtnlA//9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780085094; c=relaxed/simple; bh=0X5o/sBBZJgR5MYfozbYTR9rpssx2q3ecQBpozGXU24=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WvcHTqELuY066yZwfqnS5KN4ZTGcS1JEZof6OaeKxRWXixymsq1OIQ4mK/RXEzffZTo6tLBrzYl1vf7iCIHVr3qklymdiyENqgsvMpVQ5geUU8rrHi0v1YakcquaCLDchMHE9I+u5gTTpKDXUv4F6q7fMTehEijQ7DHxifYjPqQ= 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=B3nD+9xD; 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="B3nD+9xD" Received: by dvalin.narfation.org (Postfix) id A025120059; Fri, 29 May 2026 20:04:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1780085090; 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=iGZJJewVonXgc7yi72zbVnz4MG2LqXf2ffouEJePe4w=; b=B3nD+9xDojNhlUCNFRrfjVFVUQbJPcqvQciVtW7B1R2Nbpb3r7eFJYZFyXrh315211RU5T RAk9Ki1IjgCp9FdH4vyLrlr5FHciEHU3+5WEROTfsteKt8F5rI8m6RQyQ/SyflvcjLXDSe hMvz3+RN0rSx/OPIlm5NDHAhgpO6BtQ= From: Sven Eckelmann To: stable@vger.kernel.org Cc: Sven Eckelmann , stable@kernel.org, Yuan Tan , Yifan Wu , Juefei Pu , Xin Liu Subject: [PATCH 5.15.y] batman-adv: tvlv: reject oversized TVLV packets Date: Fri, 29 May 2026 22:04:47 +0200 Message-ID: <20260529200447.477333-1-sven@narfation.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <2026052838-lavish-unworldly-1e28@gregkh> References: <2026052838-lavish-unworldly-1e28@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 f50487e3566358b2b982b7801945e858c78ad9ab upstream. batadv_tvlv_container_ogm_append() builds a TVLV packet section from the tvlv.container_list. The total size of this section is computed by batadv_tvlv_container_list_size(), which sums the sizes of all registered containers. The return type and accumulator in batadv_tvlv_container_list_size() were u16. If the accumulated size exceeds U16_MAX, the value wraps around, causing the subsequent allocation in batadv_tvlv_container_ogm_append() to be undersized. The memcpy-style copy that follows would then write beyond the end of the allocated buffer, corrupting kernel memory. Fix this by widening the return type of batadv_tvlv_container_list_size() to size_t. In batadv_tvlv_container_ogm_append(), check the computed length against U16_MAX before proceeding, and bail out as if the allocation had failed when the limit is exceeded. Cc: stable@kernel.org Fixes: ef26157747d4 ("batman-adv: tvlv - basic infrastructure") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reviewed-by: Yuan Tan Signed-off-by: Sven Eckelmann --- net/batman-adv/tvlv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c index 4812137439708..de0c139426839 100644 --- a/net/batman-adv/tvlv.c +++ b/net/batman-adv/tvlv.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -160,10 +161,10 @@ batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version) * * Return: size of all currently registered tvlv containers in bytes. */ -static u16 batadv_tvlv_container_list_size(struct batadv_priv *bat_priv) +static size_t batadv_tvlv_container_list_size(struct batadv_priv *bat_priv) { struct batadv_tvlv_container *tvlv; - u16 tvlv_len = 0; + size_t tvlv_len = 0; lockdep_assert_held(&bat_priv->tvlv.container_list_lock); @@ -316,13 +317,17 @@ int batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv, { struct batadv_tvlv_container *tvlv; struct batadv_tvlv_hdr *tvlv_hdr; - u16 tvlv_value_len; + size_t tvlv_value_len; void *tvlv_value; int tvlv_len_ret; bool ret; spin_lock_bh(&bat_priv->tvlv.container_list_lock); tvlv_value_len = batadv_tvlv_container_list_size(bat_priv); + if (tvlv_value_len > U16_MAX) { + tvlv_len_ret = -E2BIG; + goto end; + } ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len, packet_min_len, tvlv_value_len); -- 2.47.3