Fix unlikely null dereference in mk_cred()

If krb5_encrypt_keyhelper() returns an error, the ciphertext structure
may contain a non-zero length, but it will already have freed the
pointer to its data, making encrypt_credencpart()'s subsequent attempt
to clear and free the memory fail.  Remove that logic.

Based on a patch from Jatin Nansi.

ticket: 7948 (new)
target_version: 1.12.2
tags: pullup

diff --git a/src/lib/krb5/krb/mk_cred.c b/src/lib/krb5/krb/mk_cred.c
index a31d85cac6f0368eaf9c1c1ead0706ad3ac7137f..7616c3a7a9adabdab07ca1fa967e961de66af7fb 100644 (file)
--- a/src/lib/krb5/krb/mk_cred.c
+++ b/src/lib/krb5/krb/mk_cred.c
@@ -49,13 +49,6 @@ encrypt_credencpart(krb5_context context, krb5_cred_enc_part *pcredpart,
                                   KRB5_KEYUSAGE_KRB_CRED_ENCPART, scratch,
                                   pencdata);
 
-    if (retval) {
-        memset(pencdata->ciphertext.data, 0, pencdata->ciphertext.length);
-        free(pencdata->ciphertext.data);
-        pencdata->ciphertext.length = 0;
-        pencdata->ciphertext.data = 0;
-    }
-
     memset(scratch->data, 0, scratch->length);
     krb5_free_data(context, scratch);