diff --git a/drivers/staging/lustre/lustre/libcfs/linux/linux-module.c b/drivers/staging/lustre/lustre/libcfs/linux/linux-module.c
index a5effcd9c6794b6197cd4260b561e7308a794614..e962f89683a60cdb68ee67b3070bc185d783027e 100644
--- a/drivers/staging/lustre/lustre/libcfs/linux/linux-module.c
+++ b/drivers/staging/lustre/lustre/libcfs/linux/linux-module.c
@@ -57,7 +57,7 @@ int libcfs_ioctl_getdata(char *buf, char *end, void *arg)
 		return -EINVAL;
 	}
 
-	if (hdr->ioc_len + buf >= end) {
+	if (hdr->ioc_len >= end - buf) {
 		CERROR("PORTALS: user buffer exceeds kernel buffer\n");
 		return -EINVAL;
 	}