linux-kernel - [PATCH 02/27] kconfig: fix memory leak when EOF is encountered in quotation

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Date:   Tue, 11 Dec 2018 20:00:45 +0900
From:   Masahiro Yamada <yamada.masahiro@...ionext.com>
To:     linux-kbuild@...r.kernel.org
Cc:     Ulf Magnusson <ulfalizer@...il.com>, linux-kernel@...r.kernel.org,
        Masahiro Yamada <yamada.masahiro@...ionext.com>
Subject: [PATCH 02/27] kconfig: fix memory leak when EOF is encountered in quotation

An unterminated string literal followed by new line is passed to the
parser (with "multi-line strings not supported" warning shown), then
handled properly there.

On the other hand, an unterminated string literal at end of file is
never passed to the parser, then results in memory leak.

[Test Code]

  ----------(Kconfig begin)----------
  source "Kconfig.inc"

  config A
          bool "a"
  -----------(Kconfig end)-----------

  --------(Kconfig.inc begin)--------
  config B
          bool "b\No new line at end of file
  ---------(Kconfig.inc end)---------

[Summary from Valgrind]

  Before the fix:

    LEAK SUMMARY:
       definitely lost: 16 bytes in 1 blocks
       ...

  After the fix:

    LEAK SUMMARY:
       definitely lost: 0 bytes in 0 blocks
       ...

Eliminate the memory leak path by handling this case. Of course, such
a Kconfig file is wrong already, so I will add an error message later.

Signed-off-by: Masahiro Yamada <yamada.masahiro@...ionext.com>
---

 scripts/kconfig/zconf.l | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index eeac64c..c2f577d 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -221,6 +221,8 @@ n	[A-Za-z0-9_-]
 	}
 	<<EOF>>	{
 		BEGIN(INITIAL);
+		yylval.string = text;
+		return T_WORD_QUOTE;
 	}
 }
 
-- 
2.7.4