From patchwork Mon Jul 12 06:11:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 473840 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2508C07E9C for ; Mon, 12 Jul 2021 07:24:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8663B6143E for ; Mon, 12 Jul 2021 07:24:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245192AbhGLH1e (ORCPT ); Mon, 12 Jul 2021 03:27:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:35324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241069AbhGLHZv (ORCPT ); Mon, 12 Jul 2021 03:25:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5648D61464; Mon, 12 Jul 2021 07:22:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626074568; bh=SUyU+GE1uT4cL5sO7tDyoPTBA/b+FFqdbKYcxb7qfm4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DIq8HhNKi+5DeFaIz3Gy5DygfOUH/XB/J3VnVwbMK/0wZ5cmzhV5sq0oR7xwg2Ob6 cWSes1CzBedBA9Nxmcl7Y/lb0DKRewnty1uKAk+SB1c45Ymeqp97m2mK1J35gsOSFm WsHyO/zMM6mxiCOLOU2JE1+fbPP6QEZL/mxNe+l4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Sasha Levin Subject: [PATCH 5.12 621/700] staging: gdm724x: check for overflow in gdm_lte_netif_rx() Date: Mon, 12 Jul 2021 08:11:44 +0200 Message-Id: <20210712061041.893919221@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit 7002b526f4ff1f6da34356e67085caafa6be383a ] This code assumes that "len" is at least 62 bytes, but we need a check to prevent a read overflow. Fixes: 61e121047645 ("staging: gdm7240: adding LTE USB driver") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/YMcoTPsCYlhh2TQo@mwanda Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/gdm724x/gdm_lte.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c index a41af7aa74ec..bd5f87433404 100644 --- a/drivers/staging/gdm724x/gdm_lte.c +++ b/drivers/staging/gdm724x/gdm_lte.c @@ -611,10 +611,12 @@ static void gdm_lte_netif_rx(struct net_device *dev, char *buf, * bytes (99,130,83,99 dec) */ } __packed; - void *addr = buf + sizeof(struct iphdr) + - sizeof(struct udphdr) + - offsetof(struct dhcp_packet, chaddr); - ether_addr_copy(nic->dest_mac_addr, addr); + int offset = sizeof(struct iphdr) + + sizeof(struct udphdr) + + offsetof(struct dhcp_packet, chaddr); + if (offset + ETH_ALEN > len) + return; + ether_addr_copy(nic->dest_mac_addr, buf + offset); } }