From 1403f9aa2f34e6dfd17816e63b88348d55291e45 Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Mon, 10 Jan 2011 03:49:49 +0000
Subject: [PATCH] don't free memory passed to putenv(), use malloc and check
 for malloc failures

---
 lib/dns/gssapictx.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/lib/dns/gssapictx.c b/lib/dns/gssapictx.c
index f1738c4e2f..736a9badcb 100644
--- a/lib/dns/gssapictx.c
+++ b/lib/dns/gssapictx.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: gssapictx.c,v 1.25 2011/01/08 23:47:01 tbox Exp $ */
+/* $Id: gssapictx.c,v 1.26 2011/01/10 03:49:49 marka Exp $ */
 
 #include <config.h>
 
@@ -553,7 +553,6 @@ dst_gssapi_initctx(dns_name_t *name, isc_buffer_t *intoken,
 	isc_result_t result;
 	gss_buffer_desc gnamebuf;
 	unsigned char array[DNS_NAME_MAXTEXT + 1];
-	char *tmpfile = NULL;
 
 	/* Client must pass us a valid gss_ctx_id_t here */
 	REQUIRE(gssctx != NULL);
@@ -618,11 +617,6 @@ dst_gssapi_initctx(dns_name_t *name, isc_buffer_t *intoken,
 		result = DNS_R_CONTINUE;
 
  out:
-	if (tmpfile) {
-		unsetenv("KRB5_CONFIG");
-		isc_file_remove(tmpfile);
-		isc_mem_free(mctx, tmpfile);
-	}
 	return (result);
 #else
 	UNUSED(name);
@@ -653,7 +647,6 @@ dst_gssapi_acceptctx(gss_cred_id_t cred,
 	gss_name_t gname = NULL;
 	isc_result_t result;
 	char buf[1024];
-	char *kt = NULL;
 
 	REQUIRE(outtoken != NULL && *outtoken == NULL);
 
@@ -678,9 +671,19 @@ dst_gssapi_acceptctx(gss_cred_id_t cred,
 			return (DNS_R_INVALIDTKEY);
 		}
 #else
-		kt = isc_mem_allocate(mctx, strlen(gssapi_keytab) + 13);
-		sprintf(kt, "KRB5_KTNAME=%s", gssapi_keytab);
-		putenv(kt);
+		/*
+		 * Minimize memory leakage by only setting KRB5_KTNAME
+		 * if it needs to change.
+		 */
+		const char *old = getenv("KRB5_KTNAME");
+		if (old == NULL || strcmp(old, gssapi_keytab) != 0) {
+			char *kt = malloc(strlen(gssapi_keytab) + 13);
+			if (kt == NULL)
+				return (ISC_R_NOMEMORY);
+			sprintf(kt, "KRB5_KTNAME=%s", gssapi_keytab);
+			if (putenv(kt) != 0)
+				return (ISC_R_NOMEMORY);
+		}
 #endif
 	}
 
@@ -772,9 +775,6 @@ dst_gssapi_acceptctx(gss_cred_id_t cred,
 						   sizeof(buf)));
 	}
 
-	if (kt != NULL)
-		isc_mem_free(mctx, kt);
-
 	return (result);
 #else
 	UNUSED(cred);