From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 78313C433E0 for ; Mon, 15 Feb 2021 08:45:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EDC864E6D for ; Mon, 15 Feb 2021 08:45:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229938AbhBOIpT (ORCPT ); Mon, 15 Feb 2021 03:45:19 -0500 Received: from mx2.suse.de ([195.135.220.15]:42588 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229693AbhBOIpL (ORCPT ); Mon, 15 Feb 2021 03:45:11 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1613378665; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7p0ZgJ7y6ZYSp40cSR2HClicIs9V9AmTmeD/P0zrzfM=; b=jR+Ajl9qThbiHeigkerXV0mkqJhMebC+WU2WKgJwC+evDZjAkMvChSzoKIJTaZd1NNOzBm e055hpfXlrJirRBuSzYrMeJvD0SOeSNpaI4DPTAfe6l+UNcpINMj7gDQ0SzsxV1H6Uf7lb SeZrlXHJmXen2taNgw8BLT2CjlyeqpI= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E0FC3AD78; Mon, 15 Feb 2021 08:44:24 +0000 (UTC) Date: Mon, 15 Feb 2021 09:44:24 +0100 From: Michal Hocko To: Ivan Safonov Cc: Greg Kroah-Hartman , Andrew Morton , Allen Pais , Johannes Weiner , Waiman Long , Abheek Dhawan , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] staging:wlan-ng: use memdup_user instead of kmalloc/copy_from_user Message-ID: References: <20210213120527.451531-1-insafonov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210213120527.451531-1-insafonov@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 13-02-21 15:05:28, Ivan Safonov wrote: > memdup_user() is shorter and safer equivalent > of kmalloc/copy_from_user pair. > > Signed-off-by: Ivan Safonov > --- > drivers/staging/wlan-ng/p80211netdev.c | 28 ++++++++++++-------------- > 1 file changed, 13 insertions(+), 15 deletions(-) > > diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c > index a15abb2c8f54..6f9666dc0277 100644 > --- a/drivers/staging/wlan-ng/p80211netdev.c > +++ b/drivers/staging/wlan-ng/p80211netdev.c > @@ -569,24 +569,22 @@ static int p80211knetdev_do_ioctl(struct net_device *dev, > goto bail; > } > > - /* Allocate a buf of size req->len */ > - msgbuf = kmalloc(req->len, GFP_KERNEL); > - if (msgbuf) { > - if (copy_from_user(msgbuf, (void __user *)req->data, req->len)) > - result = -EFAULT; > - else > - result = p80211req_dorequest(wlandev, msgbuf); > + msgbuf = memdup_user(req->data, req->len); Move to memdup_user is definitely a right step. What is the range of req->len though? If this can be larger than PAGE_SIZE then vmemdup_user would be a better alternative. -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9C58CC433E0 for ; Mon, 15 Feb 2021 08:44:31 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 18F3664E05 for ; Mon, 15 Feb 2021 08:44:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 18F3664E05 Authentication-Results: mail.kernel.org; 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Mon, 15 Feb 2021 08:44:27 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 3768F848A9 for ; Mon, 15 Feb 2021 08:44:27 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1613378665; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7p0ZgJ7y6ZYSp40cSR2HClicIs9V9AmTmeD/P0zrzfM=; b=jR+Ajl9qThbiHeigkerXV0mkqJhMebC+WU2WKgJwC+evDZjAkMvChSzoKIJTaZd1NNOzBm e055hpfXlrJirRBuSzYrMeJvD0SOeSNpaI4DPTAfe6l+UNcpINMj7gDQ0SzsxV1H6Uf7lb SeZrlXHJmXen2taNgw8BLT2CjlyeqpI= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E0FC3AD78; Mon, 15 Feb 2021 08:44:24 +0000 (UTC) Date: Mon, 15 Feb 2021 09:44:24 +0100 From: Michal Hocko To: Ivan Safonov Subject: Re: [PATCH] staging:wlan-ng: use memdup_user instead of kmalloc/copy_from_user Message-ID: References: <20210213120527.451531-1-insafonov@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210213120527.451531-1-insafonov@gmail.com> X-BeenThere: driverdev-devel@linuxdriverproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Driver Project Developer List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devel@driverdev.osuosl.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Johannes Weiner , Waiman Long , Andrew Morton , Allen Pais , Abheek Dhawan Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" On Sat 13-02-21 15:05:28, Ivan Safonov wrote: > memdup_user() is shorter and safer equivalent > of kmalloc/copy_from_user pair. > > Signed-off-by: Ivan Safonov > --- > drivers/staging/wlan-ng/p80211netdev.c | 28 ++++++++++++-------------- > 1 file changed, 13 insertions(+), 15 deletions(-) > > diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c > index a15abb2c8f54..6f9666dc0277 100644 > --- a/drivers/staging/wlan-ng/p80211netdev.c > +++ b/drivers/staging/wlan-ng/p80211netdev.c > @@ -569,24 +569,22 @@ static int p80211knetdev_do_ioctl(struct net_device *dev, > goto bail; > } > > - /* Allocate a buf of size req->len */ > - msgbuf = kmalloc(req->len, GFP_KERNEL); > - if (msgbuf) { > - if (copy_from_user(msgbuf, (void __user *)req->data, req->len)) > - result = -EFAULT; > - else > - result = p80211req_dorequest(wlandev, msgbuf); > + msgbuf = memdup_user(req->data, req->len); Move to memdup_user is definitely a right step. What is the range of req->len though? If this can be larger than PAGE_SIZE then vmemdup_user would be a better alternative. -- Michal Hocko SUSE Labs _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel