diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 59622366c613dcd0a5099fb83eb6b02c55a50530..05f8df866e4cf6075b638b572bae31af9e5943a4 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1472,6 +1472,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 	struct btrfs_trans_handle *trans;
 	struct btrfs_device *device = NULL;
 	char *sizestr;
+	char *retptr;
 	char *devstr = NULL;
 	int ret = 0;
 	int mod = 0;
@@ -1539,8 +1540,8 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 			mod = 1;
 			sizestr++;
 		}
-		new_size = memparse(sizestr, NULL);
-		if (new_size == 0) {
+		new_size = memparse(sizestr, &retptr);
+		if (*retptr != '\0' || new_size == 0) {
 			ret = -EINVAL;
 			goto out_free;
 		}