drm/amd/display: Fix potential NULL and mem leak in create_links

Found by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:148 create_links()
error: potential null dereference 'link->link_enc'.  (kzalloc returns
null)

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 15625fd..7240db2 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -121,6 +121,10 @@ static bool create_links(
                        goto failed_alloc;
                }
 
+               link->link_index = dc->link_count;
+               dc->links[dc->link_count] = link;
+               dc->link_count++;
+
                link->ctx = dc->ctx;
                link->dc = dc;
                link->connector_signal = SIGNAL_TYPE_VIRTUAL;
@@ -128,6 +132,12 @@ static bool create_links(
                link->link_id.id = CONNECTOR_ID_VIRTUAL;
                link->link_id.enum_id = ENUM_ID_1;
                link->link_enc = kzalloc(sizeof(*link->link_enc), GFP_KERNEL);
+
+               if (!link->link_enc) {
+                       BREAK_TO_DEBUGGER();
+                       goto failed_alloc;
+               }
+
                link->link_status.dpcd_caps = &link->dpcd_caps;
 
                enc_init.ctx = dc->ctx;
@@ -139,10 +149,6 @@ static bool create_links(
                enc_init.encoder.id = ENCODER_ID_INTERNAL_VIRTUAL;
                enc_init.encoder.enum_id = ENUM_ID_1;
                virtual_link_encoder_construct(link->link_enc, &enc_init);
-
-               link->link_index = dc->link_count;
-               dc->links[dc->link_count] = link;
-               dc->link_count++;
        }
 
        return true;