pull up r24429 from trunk

 ------------------------------------------------------------------------
 r24429 | tlyu | 2010-10-05 17:05:19 -0400 (Tue, 05 Oct 2010) | 14 lines

 ticket: 6797
 subject: CVE-2010-1322 KDC uninitialized pointer crash in authorization data handling (MITKRB5-SA-2010-006)
 tags: pullup
 target_version: 1.8.4

 When the KDC receives certain TGS-REQ messages, it may dereference an
 uninitialized pointer while processing authorization data, causing a
 crash, or in rare cases, unauthorized information disclosure, ticket
 modification, or execution of arbitrary code.  The crash may be
 triggered by legitimate requests.

 Correctly implement the filtering of authorization data items to avoid
 leaving uninitialized pointers when omitting items.

ticket: 6797
status: resolved
version_fixed: 1.8.4

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-8@24431 dc483132-0cff-0310-8789-dd5450dbe970

diff --git a/src/kdc/kdc_authdata.c b/src/kdc/kdc_authdata.c
index b5de64de20cd9b2a7c201206e42ab732b4676846..cc44e2918821b0ae1ae1f736be540595b0267caa 100644 (file)
--- a/src/kdc/kdc_authdata.c
+++ b/src/kdc/kdc_authdata.c
@@ -495,7 +495,7 @@ merge_authdata (krb5_context context,
                 krb5_boolean copy,
                 krb5_boolean ignore_kdc_issued)
 {
-    size_t i, nadata = 0;
+    size_t i, j, nadata = 0;
     krb5_authdata **authdata = *out_authdata;
 
     if (in_authdata == NULL || in_authdata[0] == NULL)
@@ -529,16 +529,16 @@ merge_authdata (krb5_context context,
         in_authdata = tmp;
     }
 
-    for (i = 0; in_authdata[i] != NULL; i++) {
+    for (i = 0, j = 0; in_authdata[i] != NULL; i++) {
         if (ignore_kdc_issued &&
             is_kdc_issued_authdatum(context, in_authdata[i], 0)) {
             free(in_authdata[i]->contents);
             free(in_authdata[i]);
         } else
-            authdata[nadata + i] = in_authdata[i];
+            authdata[nadata + j++] = in_authdata[i];
     }
 
-    authdata[nadata + i] = NULL;
+    authdata[nadata + j] = NULL;
 
     free(in_authdata);