From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754380AbYKVUaZ (ORCPT ); Sat, 22 Nov 2008 15:30:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751847AbYKVUaL (ORCPT ); Sat, 22 Nov 2008 15:30:11 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:48413 "EHLO gprs189-60.eurotel.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751602AbYKVUaK (ORCPT ); Sat, 22 Nov 2008 15:30:10 -0500 Date: Sat, 22 Nov 2008 21:31:51 +0100 From: Pavel Machek To: Andrew Morton Cc: rpurdie@rpsys.net, linux-kernel@vger.kernel.org Subject: Re: backlight: catch invalid input Message-ID: <20081122203151.GA1856@elf.ucw.cz> References: <20081121111414.GA1455@elf.ucw.cz> <20081121155421.152cc555.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081121155421.152cc555.akpm@linux-foundation.org> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew hinted that strict_strtoul is right fix. Check input properly in backlight, echo > brightness should not turn off the backlight. Signed-off-by: Pavel Machek diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 5c2e23d..e4c93fc 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -80,22 +80,18 @@ static ssize_t backlight_show_power(stru static ssize_t backlight_store_power(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int rc = -ENXIO; - char *endp; + int rc; struct backlight_device *bd = to_backlight_device(dev); - int power = simple_strtoul(buf, &endp, 0); - size_t size = endp - buf; + unsigned long power; - if (!size) - return -EINVAL; - if (*endp && isspace(*endp)) - size++; - if (size != count) - return -EINVAL; + rc = strict_strtoul(buf, 0, &power); + if (rc) + return rc; + rc = -ENXIO; mutex_lock(&bd->ops_lock); if (bd->ops) { - pr_debug("backlight: set power to %d\n", power); + pr_debug("backlight: set power to %lu\n", power); if (bd->props.power != power) { bd->props.power = power; backlight_update_status(bd); @@ -118,23 +114,22 @@ static ssize_t backlight_show_brightness static ssize_t backlight_store_brightness(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int rc = -ENXIO; - char *endp; + int rc; struct backlight_device *bd = to_backlight_device(dev); - int brightness = simple_strtoul(buf, &endp, 0); - size_t size = endp - buf; + unsigned long brightness; + + rc = strict_strtoul(buf, 0, &brightness); + if (rc) + return rc; - if (*endp && isspace(*endp)) - size++; - if (size != count) - return -EINVAL; + rc = -ENXIO; mutex_lock(&bd->ops_lock); if (bd->ops) { if (brightness > bd->props.max_brightness) rc = -EINVAL; else { - pr_debug("backlight: set brightness to %d\n", + pr_debug("backlight: set brightness to %lu\n", brightness); if (bd->props.brightness != brightness) { bd->props.brightness = brightness; -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html