NetBSD Problem Report #38677
From martin@duskware.de Sat May 17 12:58:05 2008
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Date: Sat, 17 May 2008 06:23:31 +0000 (UTC)
From: mtbakerguy@yahoo.com
Reply-To: mtbakerguy@yahoo.com
To: netbsd-bugs-owner@NetBSD.org
Subject: memory leak in getnetnamadr.c
X-Send-Pr-Version: www-1.0
>Number: 38677
>Category: lib
>Synopsis: memory leak in getnetnamadr.c
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: lib-bug-people
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sat May 17 13:00:00 +0000 2008
>Last-Modified: Sat Jun 16 06:51:25 +0000 2012
>Originator: B K
>Release: current
>Organization:
home
>Environment:
NetBSD new-host-2 4.99.60 NetBSD 4.99.60 (ZZZZ) #1: Sat Apr 19 08:46:10 PDT 2008 root@new-host-2:/usr/obj/sys/arch/i386/compile/ZZZZ i386
>Description:
Memleak found via code inspection.
Also noticed some code in getaddrinfo.c that could be made more robust* and cleaner by coalescing some memory allocation.
*as long as a single 128kb allocation is more likely to succeed than 2 separate 64kb allocations. As I write this, I wonder if the getnetnamadr leak ever gets triggered since a 64kb leak would be hard to miss.
>How-To-Repeat:
N/A --> strictly from code inspection
>Fix:
Lightly-tested diff follows:
Index: getaddrinfo.c
===================================================================
RCS file: /cvsroot/src/lib/libc/net/getaddrinfo.c,v
retrieving revision 1.91
diff -d -u -r1.91 getaddrinfo.c
--- getaddrinfo.c 19 Apr 2008 07:56:34 -0000 1.91
+++ getaddrinfo.c 17 May 2008 06:08:18 -0000
@@ -1285,17 +1285,12 @@
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
- buf = malloc(sizeof(*buf));
+ buf = malloc(sizeof(*buf) * 2);
if (buf == NULL) {
h_errno = NETDB_INTERNAL;
return NS_NOTFOUND;
}
- buf2 = malloc(sizeof(*buf2));
- if (buf2 == NULL) {
- free(buf);
- h_errno = NETDB_INTERNAL;
- return NS_NOTFOUND;
- }
+ buf2 = buf + 1;
switch (pai->ai_family) {
case AF_UNSPEC:
@@ -1328,21 +1323,18 @@
break;
default:
free(buf);
- free(buf2);
return NS_UNAVAIL;
}
res = __res_get_state();
if (res == NULL) {
free(buf);
- free(buf2);
return NS_NOTFOUND;
}
if (res_searchN(name, &q, res) < 0) {
__res_put_state(res);
free(buf);
- free(buf2);
return NS_NOTFOUND;
}
ai = getanswer(buf, q.n, q.name, q.qtype, pai);
@@ -1357,7 +1349,6 @@
cur->ai_next = ai;
}
free(buf);
- free(buf2);
if (sentinel.ai_next == NULL) {
__res_put_state(res);
switch (h_errno) {
Index: getnetnamadr.c
===================================================================
RCS file: /cvsroot/src/lib/libc/net/getnetnamadr.c,v
retrieving revision 1.40
diff -d -u -r1.40 getnetnamadr.c
--- getnetnamadr.c 8 May 2008 13:01:42 -0000 1.40
+++ getnetnamadr.c 17 May 2008 06:08:18 -0000
@@ -343,8 +343,10 @@
return NS_NOTFOUND;
}
res = __res_get_state();
- if (res == NULL)
+ if (res == NULL) {
+ free(buf);
return NS_NOTFOUND;
+ }
anslen = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf));
if (anslen < 0) {
free(buf);
>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: lib-bug-people->lukem
Responsible-Changed-By: lukem@NetBSD.org
Responsible-Changed-When: Sun, 18 May 2008 22:36:07 +0000
Responsible-Changed-Why:
I'll work on this
From: Luke Mewburn <lukem@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc:
Subject: PR/38677 CVS commit: src/lib/libc/net
Date: Sun, 18 May 2008 22:36:15 +0000 (UTC)
Module Name: src
Committed By: lukem
Date: Sun May 18 22:36:15 UTC 2008
Modified Files:
src/lib/libc/net: getnetnamadr.c
Log Message:
Fix possible memory leak in error path.
Part of PR 38677.
To generate a diff of this commit:
cvs rdiff -r1.40 -r1.41 src/lib/libc/net/getnetnamadr.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Responsible-Changed-From-To: lukem->lib-bug-people
Responsible-Changed-By: lukem@NetBSD.org
Responsible-Changed-When: Sat, 16 Jun 2012 06:51:25 +0000
Responsible-Changed-Why:
I'm not going to get time to finish this
>Unformatted:
(Contact us)
$NetBSD: query-full-pr,v 1.39 2013/11/01 18:47:49 spz Exp $
$NetBSD: gnats_config.sh,v 1.8 2006/05/07 09:23:38 tsutsui Exp $
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