[PATCH] Fix getaddrinfo leaking memory

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

If getaddrinfo is called without _res initialized, it will leak memory
until some other function is called which initializes it.
The problem is that gaih_inet saves old options (0 in this case) and
after lookup (which as a side-effect initialized it) restores _res.option
from the saved value (which means next time _res will be initialized
again).  Also, if _res has not been initialized before getaddrinfo, the
_res.options &= ~RES_USE_INET6 line is a nop (it will be initialized
to RES_USE_INET6 during initialization anyway).
The following patch fixes it.

2004-02-23  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/posix/getaddrinfo.c (gaih_inet): If _res has not been
	inited yet, try to init it before saving old _res.options.
	* posix/Makefile (xtests): Add bug-ga2.
	(generated): Add bug-ga2.mtrace and bug-ga2-mem.
	(xtests): Depend on bug-ga2-mem.
	($(objpfx)bug-ga2-mem, bug-ga2-ENV): New.
	* posix/bug-ga2.c: New test.

--- libc/sysdeps/posix/getaddrinfo.c.jj	2004-02-19 17:50:44.000000000 +0100
+++ libc/sysdeps/posix/getaddrinfo.c	2004-02-23 11:18:46.516227127 +0100
@@ -604,8 +604,6 @@ gaih_inet (const char *name, const struc
 	  struct gaih_addrtuple **pat = &at;
 	  int no_data = 0;
 	  int no_inet6_data = 0;
-	  int old_res_options = _res.options;
-
 	  /* If we are looking for both IPv4 and IPv6 address we don't
 	     want the lookup functions to automatically promote IPv4
 	     addresses to IPv6 addresses.  Currently this is decided
@@ -616,6 +614,7 @@ gaih_inet (const char *name, const struc
 	      enum nss_status inet6_status, status = NSS_STATUS_UNAVAIL;
 	      int no_more;
 	      nss_gethostbyname2_r fct;
+	      int old_res_options;
 
 	      if (__nss_hosts_database != NULL)
 		{
@@ -626,6 +625,9 @@ gaih_inet (const char *name, const struc
 		no_more = __nss_database_lookup ("hosts", NULL,
 						 "dns [!UNAVAIL=return] files", &nip);
 
+	      if ((_res.options & RES_INIT) == 0 && __res_ninit(&_res) == -1)
+		no_more = 1;
+	      old_res_options = _res.options;
 	      _res.options &= ~RES_USE_INET6;
 
 	      while (!no_more)
--- libc/posix/Makefile.jj	2004-02-19 17:50:41.000000000 +0100
+++ libc/posix/Makefile	2004-02-23 11:44:24.020830312 +0100
@@ -82,6 +82,7 @@ tests		:= tstgetopt testfnm runtests run
 		   bug-regex21 bug-regex22 bug-regex23 tst-nice tst-nanosleep \
 		   transbug tst-rxspencer tst-pcre tst-boost \
 		   bug-ga1
+xtests		:= bug-ga2
 ifeq (yes,$(build-shared))
 test-srcs	:= globtest
 tests           += wordexp-test tst-exec tst-spawn
@@ -98,7 +99,8 @@ generated := $(addprefix wordexp-test-re
 	     bug-regex2.mtrace bug-regex14-mem bug-regex14.mtrace \
 	     bug-regex21-mem bug-regex21.mtrace \
 	     tst-rxspencer-mem tst-rxspencer.mtrace tst-getconf.out \
-	     tst-pcre-mem tst-pcre.mtrace tst-boost-mem tst-boost.mtrace
+	     tst-pcre-mem tst-pcre.mtrace tst-boost-mem tst-boost.mtrace \
+	     bug-ga2.mtrace bug-ga2-mem
 
 include ../Rules
 
@@ -191,6 +193,7 @@ ifeq (no,$(cross-compiling))
 tests: $(objpfx)bug-regex2-mem $(objpfx)bug-regex14-mem \
   $(objpfx)bug-regex21-mem $(objpfx)tst-rxspencer-mem \
   $(objpfx)tst-pcre-mem $(objpfx)tst-boost-mem $(objpfx)tst-getconf.out
+xtests: $(objpfx)bug-ga2-mem
 endif
 
 $(objpfx)annexc.out: $(objpfx)annexc
@@ -241,3 +244,8 @@ $(objpfx)tst-regex: $(common-objpfx)rt/l
 else
 $(objpfx)tst-regex: $(common-objpfx)rt/librt.a
 endif
+
+$(objpfx)bug-ga2-mem: $(objpfx)bug-ga2.out
+	$(common-objpfx)malloc/mtrace $(objpfx)bug-ga2.mtrace > $@
+
+bug-ga2-ENV = MALLOC_TRACE=$(objpfx)bug-ga2.mtrace
--- libc/posix/bug-ga2.c.jj	2004-02-23 11:37:37.900002974 +0100
+++ libc/posix/bug-ga2.c	2004-02-23 11:39:39.617084575 +0100
@@ -0,0 +1,30 @@
+/* Test case by Sam Varshavchik <mrsam@courier-mta.com>.  */
+#include <mcheck.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <string.h>
+
+int
+main (void)
+{
+  struct addrinfo hints, *res;
+  int i, ret;
+
+  mtrace ();
+  for (i = 0; i < 100; i++)
+    {
+      memset (&hints, 0, sizeof (hints));
+      hints.ai_family = PF_UNSPEC;
+      hints.ai_socktype = SOCK_STREAM;
+
+      ret = getaddrinfo ("www.gnu.org", "http", &hints, &res);
+
+      if (ret)
+	{
+	  printf ("%s\n", gai_strerror (ret));
+	  return 1;
+	}
+      freeaddrinfo (res);
+    }
+  return 0;
+}

	Jakub