From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50678 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730523AbeKLFsY (ORCPT ); Mon, 12 Nov 2018 00:48:24 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jacek Anaszewski" , "Zach Brown" , "Vlastimil Babka" , "Nathan Sullivan" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: Subject: [PATCH 3.16 331/366] leds: do not overflow sysfs buffer in led_trigger_show In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Nathan Sullivan commit 3b9b95363c45365d606ad4bbba16acca75fdf6d3 upstream. 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 Signed-off-by: Jacek Anaszewski Cc: Vlastimil Babka Signed-off-by: Ben Hutchings --- drivers/leds/led-triggers.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -78,21 +78,23 @@ ssize_t led_trigger_show(struct device * 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);