diff --git a/drivers/gpu/drm/nouveau/nouveau_pm.c b/drivers/gpu/drm/nouveau/nouveau_pm.c
index 34d591b7d4ef..da3e7c3abab7 100644
--- a/drivers/gpu/drm/nouveau/nouveau_pm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_pm.c
@@ -235,6 +235,7 @@ nouveau_pm_profile_set(struct drm_device *dev, const char *profile)
 		return -EPERM;
 
 	strncpy(string, profile, sizeof(string));
+	string[sizeof(string) - 1] = 0;
 	if ((ptr = strchr(string, '\n')))
 		*ptr = '\0';