staging: android: ion: Fix error handling in ion_query_heaps()

If the copy_to_user() fails we should unlock and return directly without
updating "cnt".  Also the return value should be -EFAULT instead of the
number of bytes remaining.

Fixes: 02b23803c6af ("staging: android: ion: Add ioctl to query available heaps")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 396ded5..209a8f7 100644 (file)
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -1187,8 +1187,10 @@ int ion_query_heaps(struct ion_client *client, struct ion_heap_query *query)
                hdata.type = heap->type;
                hdata.heap_id = heap->id;
 
-               ret = copy_to_user(&buffer[cnt],
-                                  &hdata, sizeof(hdata));
+               if (copy_to_user(&buffer[cnt], &hdata, sizeof(hdata))) {
+                       ret = -EFAULT;
+                       goto out;
+               }
 
                cnt++;
                if (cnt >= max_cnt)