kconfig: Fix automatic menu creation mem leak

[ Upstream commit ae7440ef0c8013d68c00dad6900e7cce5311bb1c ]

expr_trans_compare() always allocates and returns a new expression,
giving the following leak outline:

	...
	*Allocate*
	basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
	...
	for (menu = parent->next; menu; menu = menu->next) {
		...
		*Copy*
		dep2 = expr_copy(basedep);
		...
		*Free copy*
		expr_free(dep2);
	}
	*basedep lost!*

Fix by freeing 'basedep' after the loop.

Summary from Valgrind on 'menuconfig' (ARCH=x86) before the fix:

	LEAK SUMMARY:
	   definitely lost: 344,376 bytes in 14,349 blocks
	   ...

Summary after the fix:

	LEAK SUMMARY:
	   definitely lost: 44,448 bytes in 1,852 blocks
	   ...

Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index e9357931b47db3fdf7f63da842a045697e038ed9..749c2bd5fc51066fb7a8ad66d513df3b8900ab71 100644 (file)
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -372,6 +372,7 @@ void menu_finalize(struct menu *parent)
                        menu->parent = parent;
                        last_menu = menu;
                }
+               expr_free(basedep);
                if (last_menu) {
                        parent->list = parent->next;
                        parent->next = last_menu->next;