[src/trunk]: src/usr.bin/make make: fix memory leak when parsing a variable name

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/591604dd12c7
branches:  trunk
changeset: 1027618:591604dd12c7
user:      rillig <rillig%NetBSD.org@localhost>
date:      Mon Dec 13 04:18:01 2021 +0000

description:
make: fix memory leak when parsing a variable name

To trigger the memory leak, the expanded variable name must not be a
prefix of the textual variable name.

        textual name            expanded name
ok:     UNDEF.${undef}          UNDEF.
leak:   UNDEF.${undef}.         UNDEF..

diffstat:

 usr.bin/make/var.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diffs (26 lines):

diff -r 99b3042faaa2 -r 591604dd12c7 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Mon Dec 13 03:55:16 2021 +0000
+++ b/usr.bin/make/var.c        Mon Dec 13 04:18:01 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.985 2021/12/13 03:55:16 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.986 2021/12/13 04:18:01 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -140,7 +140,7 @@
 #include "metachar.h"
 
 /*     "@(#)var.c      8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.985 2021/12/13 03:55:16 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.986 2021/12/13 04:18:01 rillig Exp $");
 
 /*
  * Variables are defined using one of the VAR=value assignments.  Their
@@ -4433,6 +4433,7 @@
                        *out_false_pp = p;
                        *out_false_res = EvalUndefined(dynamic, start, p,
                            name, emode, out_false_val);
+                       LazyBuf_Done(&varname);
                        return false;
                }