[PATCH 1/1] cmd/extension: avoid NULL pointer dereference

[Heinrich Schuchardt]

extension_get_list() will return NULL if there is no extension device.
Check for this situation.

Addresses-Coverity-ID: 638557 - Null pointer dereferences (NULL_RETURNS)
Fixes: 2d12958ee71b ("boot: Remove legacy extension board support")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
 cmd/extension_board.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/cmd/extension_board.c b/cmd/extension_board.c
index 86e4795ba8a..75358abf666 100644
--- a/cmd/extension_board.c
+++ b/cmd/extension_board.c
@@ -99,6 +99,10 @@ static int do_extension_list(struct cmd_tbl *cmdtp, int flag,
 	int i = 0;
 
 	extension_list = extension_get_list();
+	if (!extension_list) {
+		printf("No extension device\n");
+		return CMD_RET_FAILURE;
+	}
 	if (!alist_get_ptr(extension_list, 0)) {
 		printf("No extension registered - Please run \"extension scan\"\n");
 		return CMD_RET_SUCCESS;
-- 
2.51.0