From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932543Ab1EFAiZ (ORCPT ); Thu, 5 May 2011 20:38:25 -0400 Received: from kroah.org ([198.145.64.141]:37353 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932507Ab1EFA0E (ORCPT ); Thu, 5 May 2011 20:26:04 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Thu May 5 17:22:18 2011 Message-Id: <20110506002218.146106510@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Thu, 05 May 2011 17:21:56 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ben Hutchings , "David S. Miller" Subject: [131/143] niu: Fix kernel buffer overflow for ETHTOOL_GRXCLSRLALL In-Reply-To: <20110506002311.GA15354@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Ben Hutchings commit ee9c5cfad29c8a13199962614b9b16f1c4137ac9 upstream. niu_get_ethtool_tcam_all() assumes that its output buffer is the right size, and warns before returning if it is not. However, the output buffer size is under user control and ETHTOOL_GRXCLSRLALL is an unprivileged ethtool command. Therefore this is at least a local denial-of-service vulnerability. Change it to check before writing each entry and to return an error if the buffer is already full. Compile-tested only. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller [Adjusted to apply to 2.6.32 by dann frazier ] Signed-off-by: Greg Kroah-Hartman --- drivers/net/niu.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) --- a/drivers/net/niu.c +++ b/drivers/net/niu.c @@ -7315,33 +7315,28 @@ static int niu_get_ethtool_tcam_all(stru struct niu_parent *parent = np->parent; struct niu_tcam_entry *tp; int i, idx, cnt; - u16 n_entries; unsigned long flags; - + int ret = 0; /* put the tcam size here */ nfc->data = tcam_get_size(np); niu_lock_parent(np, flags); - n_entries = nfc->rule_cnt; for (cnt = 0, i = 0; i < nfc->data; i++) { idx = tcam_get_index(np, i); tp = &parent->tcam[idx]; if (!tp->valid) continue; + if (cnt == nfc->rule_cnt) { + ret = -EMSGSIZE; + break; + } rule_locs[cnt] = i; cnt++; } niu_unlock_parent(np, flags); - if (n_entries != cnt) { - /* print warning, this should not happen */ - pr_info(PFX "niu%d: %s In niu_get_ethtool_tcam_all, " - "n_entries[%d] != cnt[%d]!!!\n\n", - np->parent->index, np->dev->name, n_entries, cnt); - } - - return 0; + return ret; } static int niu_get_nfc(struct net_device *dev, struct ethtool_rxnfc *cmd,