From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mundt Subject: [PATCH] fb: sm501fb off-by-1 sysfs store Date: Thu, 1 Mar 2007 17:24:56 +0900 Message-ID: <20070301082456.GA3701@linux-sh.org> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1HMgdO-0007Gc-K6 for linux-fbdev-devel@lists.sourceforge.net; Thu, 01 Mar 2007 00:27:30 -0800 Received: from smtp.ocgnet.org ([64.20.243.3]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1HMgdN-0006lo-8J for linux-fbdev-devel@lists.sourceforge.net; Thu, 01 Mar 2007 00:27:30 -0800 Content-Disposition: inline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: Ben Dooks Cc: linux-fbdev-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Currently sm501fb_crtsrc_store() won't allow the routing to be changed via echos from userspace in to the sysfs file. The reason for this is that the strnicmp() for both heads uses a sizeof() for the string length, which ends up being strlen() + 1 (\0 in the normal case, but the echo gives a newline, which is where the issue occurs), this then causes a mismatch and subsequently bails with the -EINVAL. In addition to this, the hardcoded lengths were then used for the store length that was returned, which ended up being erroneous and resulting in a write error. There's also no point in returning anything but the full length since it will -EINVAL out on a mismatch well before then anyways. sizeof("string") is great for making sure you have space in your buffer, but rather less so for string comparisons :-) Signed-off-by: Paul Mundt -- drivers/video/sm501fb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c index 02b290c..72b5358 100644 --- a/drivers/video/sm501fb.c +++ b/drivers/video/sm501fb.c @@ -1074,9 +1074,9 @@ static ssize_t sm501fb_crtsrc_store(struct device *dev, if (len < 1) return -EINVAL; - if (strnicmp(buf, "crt", sizeof("crt")) == 0) + if (strnicmp(buf, "crt", 3) == 0) head = HEAD_CRT; - else if (strnicmp(buf, "panel", sizeof("panel")) == 0) + else if (strnicmp(buf, "panel", 5) == 0) head = HEAD_PANEL; else return -EINVAL; @@ -1098,7 +1098,7 @@ static ssize_t sm501fb_crtsrc_store(struct device *dev, writel(ctrl, info->regs + SM501_DC_CRT_CONTROL); sm501fb_sync_regs(info); - return (head == HEAD_CRT) ? 3 : 5; + return len; } /* Prepare the device_attr for registration with sysfs later */ ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV