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>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 396ded52ab70..209a8f7ef02b 100644
--- 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)