library/1907: small memory leak in res_init (gethostbyname)

[andrew@etunnels.com]

>Number:         1907
>Category:       library
>Synopsis:       small memory leak in res_init (gethostbyname)
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jun 29 18:10:01 MDT 2001
>Last-Modified:
>Originator:     Andrew Campbell
>Organization:
net
>Release:        2.8, 2.9
>Environment:
	
	System      : OpenBSD 2.8
	Architecture: OpenBSD.i386
	Machine     : i386
>Description:
	

        In src/lib/libc/net/res_init.c, a call is made to
        getaddrinfo(), with no corresponding call to freeaddrinfo().
        This results in a one-time leak of 48 bytes (wahoo!).

>How-To-Repeat:
	<code/input/activities to reproduce the problem (multiple
	lines)>
>Fix:
	<how to correct or work around the problem, if known (multiple
	lines)>
        Here's a patch to the 2.8 version of res_init.c that fixes the
	leak:


> cvs diff res_init.c
Index: res_init.c
===================================================================
RCS file: /cvs/src/lib/libc/net/res_init.c,v
retrieving revision 1.19
diff -u -r1.19 res_init.c
--- res_init.c  2000/06/22 07:31:18     1.19
+++ res_init.c  2001/06/29 23:51:03
@@ -355,6 +355,7 @@
                    char *q;
                    struct addrinfo hints, *res;
                    char pbuf[NI_MAXSERV];
+                   int error;
 #else
                    struct in_addr a;
 #endif /* INET6 */
@@ -375,7 +376,7 @@
                    hints.ai_flags = AI_NUMERICHOST;
                    hints.ai_socktype = SOCK_DGRAM;
                    snprintf(pbuf, sizeof(pbuf), "%d",
                    NAMESERVER_PORT);
-                   if (getaddrinfo(cp, pbuf, &hints, &res) == 0 &&
+                   if ((error = getaddrinfo(cp, pbuf, &hints, &res))
== 0 &&
                            res->ai_next == NULL) {
                        if (res->ai_addrlen <=
                        sizeof(_res_ext.nsaddr_list[nserv])) {
                            memcpy(&_res_ext.nsaddr_list[nserv],
                            res->ai_addr,
@@ -393,6 +394,8 @@
                        }
                        nserv++;
                    }
+                   if (!error)
+                        freeaddrinfo(res);
 #else /* INET6 */
                    if ((*cp != '\0') && (*cp != '\n') &&
                    inet_aton(cp, &a)) {
                        _res.nsaddr_list[nserv].sin_addr = a;

>Audit-Trail:
>Unformatted: