diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index b5f0543ed84d..f445b9cd60fb 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -416,7 +416,8 @@ static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
 
 	mutex_lock(&pm_mutex);
 	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
-		if (!strncmp(buf, hibernation_modes[i], len)) {
+		if (len == strlen(hibernation_modes[i])
+		    && !strncmp(buf, hibernation_modes[i], len)) {
 			mode = i;
 			break;
 		}
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b98b80ccf437..8812985f3029 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -290,13 +290,13 @@ static ssize_t state_store(struct kset *kset, const char *buf, size_t n)
 	len = p ? p - buf : n;
 
 	/* First, check if we are requested to hibernate */
-	if (!strncmp(buf, "disk", len)) {
+	if (len == 4 && !strncmp(buf, "disk", len)) {
 		error = hibernate();
 		return error ? error : n;
 	}
 
 	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
-		if (*s && !strncmp(buf, *s, len))
+		if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
 			break;
 	}
 	if (state < PM_SUSPEND_MAX && *s)