drm/radeon/kms: Fix NULL pointer dereference if memory allocation failed.

When there is allocation failure in radeon_cs_parser_relocs parser->nrelocs
is not cleaned. This causes NULL pointer defeference in radeon_cs_parser_fini
when clean up code is trying to loop over the relocation array and free the
objects.

Fix adds a check for a possible NULL pointer in clean up code.

Signed-off-by: Pauli Nieminen <suokkos@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index dd190f9315d3..f9b0fe002c0a 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -193,9 +193,11 @@ static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error)
                 radeon_bo_list_fence(&parser->validated, parser->ib->fence);
         }
         radeon_bo_list_unreserve(&parser->validated);
-        for (i = 0; i < parser->nrelocs; i++) {
-                if (parser->relocs[i].gobj)
-                        drm_gem_object_unreference_unlocked(parser->relocs[i].gobj);
+        if (parser->relocs != NULL) {
+                for (i = 0; i < parser->nrelocs; i++) {
+                        if (parser->relocs[i].gobj)
+                                drm_gem_object_unreference_unlocked(parser->relocs[i].gobj);
+                }
         }
         kfree(parser->track);
         kfree(parser->relocs);