[PATCH 2/3] efi_loader: Prevent dereference of uninitialised variable

[Andrew Goodbody]

If phandler is returned as NULL from efi_search_protocol then
protocol_interface is never assigned to. Add a check to prevent
protocol_interface being dereferenced in this case. Small refactor to
coalesce the two identical NULL checks of phandler.

This issue found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody at linaro.org>
---
 lib/efi_loader/efi_http.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/efi_loader/efi_http.c b/lib/efi_loader/efi_http.c
index 189317fe2d2..ce3a7a831ca 100644
--- a/lib/efi_loader/efi_http.c
+++ b/lib/efi_loader/efi_http.c
@@ -463,18 +463,18 @@ static efi_status_t EFIAPI efi_http_service_binding_destroy_child(
 
 	efi_search_protocol(child_handle, &efi_http_guid, &phandler);
 
-	if (phandler)
-		protocol_interface = phandler->protocol_interface;
-
 	ret = efi_delete_handle(child_handle);
 	if (ret != EFI_SUCCESS)
 		return EFI_EXIT(ret);
 
-	http_instance = (struct efi_http_instance *)protocol_interface;
-	efi_free_pool(http_instance->http_load_addr);
-	http_instance->http_load_addr = NULL;
+	if (phandler) {
+		protocol_interface = phandler->protocol_interface;
+		http_instance = (struct efi_http_instance *)protocol_interface;
+		efi_free_pool(http_instance->http_load_addr);
+		http_instance->http_load_addr = NULL;
 
-	free(protocol_interface);
+		free(protocol_interface);
+	}
 
 	num_instances--;
 

-- 
2.39.5