drm/amdgpu/atom: Check kcalloc() for WS buffer in amdgpu_atom_execute_table_locked()

kcalloc() may fail. When WS is non-zero and allocation fails, ectx.ws
remains NULL while ectx.ws_size is set, leading to a potential NULL
pointer dereference in atom_get_src_int() when accessing WS entries.

Return -ENOMEM on allocation failure to avoid the NULL dereference.

Signed-off-by: Guangshuo Li <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: lgs2513

drivers/gpu/drm/amd/amdgpu/atom.c

@@ -1246,6 +1246,10 @@ static int amdgpu_atom_execute_table_locked(struct atom_context *ctx, int index,
 	ectx.last_jump_jiffies = 0;
 	if (ws) {
 		ectx.ws = kcalloc(4, ws, GFP_KERNEL);
+		if (!ectx.ws) {
+			ret = -ENOMEM;
+			goto free;
+		}
 		ectx.ws_size = ws;
 	} else {
 		ectx.ws = NULL;