From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752085AbcEWVCf (ORCPT ); Mon, 23 May 2016 17:02:35 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:50255 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751625AbcEWVCd (ORCPT ); Mon, 23 May 2016 17:02:33 -0400 Date: Mon, 23 May 2016 14:02:32 -0700 (PDT) Message-Id: <20160523.140232.31037641382794779.davem@davemloft.net> To: falakreyaz@gmail.com Cc: kas@fi.muni.cz, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] wan: cosa: use memdup_user(). From: David Miller In-Reply-To: <1463746806-23739-1-git-send-email-falakreyaz@gmail.com> References: <1463746806-23739-1-git-send-email-falakreyaz@gmail.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Mon, 23 May 2016 14:02:33 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Muhammad Falak R Wani Date: Fri, 20 May 2016 17:50:06 +0530 > Use memdup_user to duplicate a memory region from user-space to > kernel-space, instead of open coding using kmalloc & copy_from_user. > > Signed-off-by: Muhammad Falak R Wani > --- > drivers/net/wan/cosa.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c > index b87fe0a..fb37439 100644 > --- a/drivers/net/wan/cosa.c > +++ b/drivers/net/wan/cosa.c > @@ -876,15 +876,10 @@ static ssize_t cosa_write(struct file *file, > count = COSA_MTU; > > /* Allocate the buffer */ > - kbuf = kmalloc(count, GFP_KERNEL|GFP_DMA); > - if (kbuf == NULL) { > + kbuf = memdup_user(buf, count); You're losing the GFP_DMA specification here, therefore this change is not correct.