From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH] leds: do not overflow sysfs buffer in led_trigger_show Date: Tue, 16 Aug 2016 22:39:56 +0200 Message-ID: <57B37A1C.2070707@gmail.com> References: <1471299614-10415-1-git-send-email-zach.brown@ni.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1471299614-10415-1-git-send-email-zach.brown@ni.com> Sender: linux-kernel-owner@vger.kernel.org To: Zach Brown , rpurdie@rpsys.net, j.anaszewski@samsung.com Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, nathan.sullivan@ni.com List-Id: linux-leds@vger.kernel.org Hi Zach, On 08/16/2016 12:20 AM, Zach Brown wrote: > From: Nathan Sullivan > > Per the documentation, use scnprintf instead of sprintf to ensure there > is never more than PAGE_SIZE bytes of trigger names put into the > buffer. > > Signed-off-by: Nathan Sullivan > Signed-off-by: Zach Brown > --- > drivers/leds/led-triggers.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c > index c92702a..8668538 100644 > --- a/drivers/leds/led-triggers.c > +++ b/drivers/leds/led-triggers.c > @@ -81,21 +81,23 @@ ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr, > down_read(&led_cdev->trigger_lock); > > if (!led_cdev->trigger) > - len += sprintf(buf+len, "[none] "); > + len += scnprintf(buf+len, PAGE_SIZE - len, "[none] "); > else > - len += sprintf(buf+len, "none "); > + len += scnprintf(buf+len, PAGE_SIZE - len, "none "); > > list_for_each_entry(trig, &trigger_list, next_trig) { > if (led_cdev->trigger && !strcmp(led_cdev->trigger->name, > trig->name)) > - len += sprintf(buf+len, "[%s] ", trig->name); > + len += scnprintf(buf+len, PAGE_SIZE - len, "[%s] ", > + trig->name); > else > - len += sprintf(buf+len, "%s ", trig->name); > + len += scnprintf(buf+len, PAGE_SIZE - len, "%s ", > + trig->name); > } > up_read(&led_cdev->trigger_lock); > up_read(&triggers_list_lock); > > - len += sprintf(len+buf, "\n"); > + len += scnprintf(len+buf, PAGE_SIZE - len, "\n"); > return len; > } > EXPORT_SYMBOL_GPL(led_trigger_show); > Thanks for the patch, applied. -- Best regards, Jacek Anaszewski