From ee061da8d9dfc30ced06f25c18694cffa70eac1e Mon Sep 17 00:00:00 2001 From: Andrew Lutomirski Date: Tue, 29 Nov 2016 17:11:50 -0800 Subject: [PATCH] PM / QoS: Improve sysfs pm_qos_latency_tolerance validation Negative values are special. Don't let users write them directly. Signed-off-by: Andy Lutomirski Signed-off-by: Rafael J. Wysocki --- drivers/base/power/sysfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index a7b46798c81d..33b4b902741a 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -263,7 +263,11 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev, s32 value; int ret; - if (kstrtos32(buf, 0, &value)) { + if (kstrtos32(buf, 0, &value) == 0) { + /* Users can't write negative values directly */ + if (value < 0) + return -EINVAL; + } else { if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n")) value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))