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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Ulf Magnusson <ulfalizer@gmail.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.15 055/189] kconfig: Fix automatic menu creation
 mem leak
Thread-Topic: [PATCH AUTOSEL for 4.15 055/189] kconfig: Fix automatic menu
 creation mem leak
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Date:   Mon, 9 Apr 2018 00:17:29 +0000
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From: Ulf Magnusson <ulfalizer@gmail.com>

[ Upstream commit ae7440ef0c8013d68c00dad6900e7cce5311bb1c ]

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

	...
	*Allocate*
	basedep =3D expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
	...
	for (menu =3D parent->next; menu; menu =3D menu->next) {
		...
		*Copy*
		dep2 =3D expr_copy(basedep);
		...
		*Free copy*
		expr_free(dep2);
	}
	*basedep lost!*

Fix by freeing 'basedep' after the loop.

Summary from Valgrind on 'menuconfig' (ARCH=3Dx86) 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>
---
 scripts/kconfig/menu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index e9357931b47d..749c2bd5fc51 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/menu.c
@@ -372,6 +372,7 @@ void menu_finalize(struct menu *parent)
 			menu->parent =3D parent;
 			last_menu =3D menu;
 		}
+		expr_free(basedep);
 		if (last_menu) {
 			parent->list =3D parent->next;
 			parent->next =3D last_menu->next;
--=20
2.15.1