| From | Ben Hutchings <> | Date | Sun, 11 Nov 2018 19:49:05 +0000 | Subject | [PATCH 3.16 331/366] leds: do not overflow sysfs buffer in led_trigger_show |
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3.16.61-rc1 review patch. If anyone has any objections, please let me know.
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From: Nathan Sullivan <nathan.sullivan@ni.com>
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 <nathan.sullivan@ni.com> Signed-off-by: Zach Brown <zach.brown@ni.com> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- 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);
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