From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752920AbcBVTbO (ORCPT ); Mon, 22 Feb 2016 14:31:14 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:43830 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752339AbcBVTbM (ORCPT ); Mon, 22 Feb 2016 14:31:12 -0500 Date: Mon, 22 Feb 2016 22:30:46 +0300 From: Dan Carpenter To: Greg Kroah-Hartman Cc: Julia Lawall , Masanari Iida , Alison Schofield , Shraddha Barke , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [patch 1/6] staging: gdm72xx: underflow in netlink_rcv_cb() Message-ID: <20160222193046.GA23565@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If nlh->nlmsg_len is less than ND_IFINDEX_LEN we end up trying to memcpy a negative size. I also re-ordered slighty the condition to make it more uniform. Signed-off-by: Dan Carpenter diff --git a/drivers/staging/gdm72xx/netlink_k.c b/drivers/staging/gdm72xx/netlink_k.c index cf0b47c..4089b17 100644 --- a/drivers/staging/gdm72xx/netlink_k.c +++ b/drivers/staging/gdm72xx/netlink_k.c @@ -55,7 +55,8 @@ static void netlink_rcv_cb(struct sk_buff *skb) if (skb->len >= NLMSG_HDRLEN) { nlh = (struct nlmsghdr *)skb->data; - if (skb->len < nlh->nlmsg_len || + if (nlh->nlmsg_len < ND_IFINDEX_LEN || + nlh->nlmsg_len > skb->len || nlh->nlmsg_len > ND_MAX_MSG_LEN) { netdev_err(skb->dev, "Invalid length (%d,%d)\n", skb->len, nlh->nlmsg_len);