From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932128Ab1HCX2X (ORCPT ); Wed, 3 Aug 2011 19:28:23 -0400 Received: from cantor2.suse.de ([195.135.220.15]:33728 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932118Ab1HCX2K (ORCPT ); Wed, 3 Aug 2011 19:28:10 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Aug 3 15:12:47 2011 Message-Id: <20110803221246.917881526@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 03 Aug 2011 15:00:49 -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: [029/102] ethtool: Allow zero-length register dumps again In-Reply-To: <20110803221345.GA10346@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let us know. ------------------ From: Ben Hutchings commit 67ae7cf1eeda777f79259c4c6cb17a0bd28dee71 upstream. Some drivers (ab)use the ethtool_ops::get_regs operation to expose only a hardware revision ID. Commit a77f5db361ed9953b5b749353ea2c7fed2bf8d93 ('ethtool: Allocate register dump buffer with vmalloc()') had the side-effect of breaking these, as vmalloc() returns a null pointer for size=0 whereas kmalloc() did not. For backward-compatibility, allow zero-length dumps again. Reported-by: Kalle Valo Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/ethtool.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -1227,7 +1227,7 @@ static int ethtool_get_regs(struct net_d regs.len = reglen; regbuf = vzalloc(reglen); - if (!regbuf) + if (reglen && !regbuf) return -ENOMEM; ops->get_regs(dev, ®s, regbuf); @@ -1236,7 +1236,7 @@ static int ethtool_get_regs(struct net_d if (copy_to_user(useraddr, ®s, sizeof(regs))) goto out; useraddr += offsetof(struct ethtool_regs, data); - if (copy_to_user(useraddr, regbuf, regs.len)) + if (regbuf && copy_to_user(useraddr, regbuf, regs.len)) goto out; ret = 0;