[PATCH AUTOSEL for 4.14 048/161] kconfig: Fix expr_free() E_NOT leak

Sasha Levin
2018-04-09T03:20:21Z

From: Ulf Magnusson <ulfalizer@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 <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
scripts/kconfig/expr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
index cbf4996dd9c1..ed29bad1f03a 100644
--- a/scripts/kconfig/expr.c
+++ b/scripts/kconfig/expr.c
@@ -113,7 +113,7 @@ void expr_free(struct expr *e)
break;
case E_NOT:
expr_free(e->left.expr);
- return;
+ break;
case E_EQUAL:
case E_GEQ:
case E_GTH:
--
2.15.1