[PATCH 3.18 021/185] kconfig: Fix expr_free() E_NOT leak

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ulf Magnusson <ulfali...@gmail.com>

[ Upstream commit 5b1374b3b3c2fc4f63a398adfa446fb8eff791a4 ]

Only the E_NOT operand and not the E_NOT node itself was freed, due to
accidentally returning too early in expr_free(). Outline of leak:

        switch (e->type) {
        ...
        case E_NOT:
                expr_free(e->left.expr);
                return;
        ...
        }
        *Never reached, 'e' leaked*
        free(e);

Fix by changing the 'return' to a 'break'.

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

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

Summary after the fix:

        LEAK SUMMARY:
           definitely lost: 1,608 bytes in 67 blocks
           ...

Signed-off-by: Ulf Magnusson <ulfali...@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 scripts/kconfig/expr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/scripts/kconfig/expr.c
+++ b/scripts/kconfig/expr.c
@@ -106,7 +106,7 @@ void expr_free(struct expr *e)
                break;
        case E_NOT:
                expr_free(e->left.expr);
-               return;
+               break;
        case E_EQUAL:
        case E_UNEQUAL:
                break;