Fix handling of invalid CAMMAC service verifier

In extract_cammacs(), avoid a null dereference if the CAMMAC service
verifier is invalid or the CAMMAC is empty.

(cherry picked from commit 8451ff6ed57361de585a35f35a39c54dc48172c7)

ticket: 8856
version_fixed: 1.17.2

diff --git a/src/lib/krb5/krb/authdata.c b/src/lib/krb5/krb/authdata.c
index 7fbcfab686ce7d5cd82f26e60cd1fdb94802e218..12ac92dff757110695e145890cb9ac10d262e027 100644 (file)
--- a/src/lib/krb5/krb/authdata.c
+++ b/src/lib/krb5/krb/authdata.c
@@ -557,6 +557,8 @@ extract_cammacs(krb5_context kcontext, krb5_authdata **cammacs,
         if (ret && ret != KRB5KRB_AP_ERR_BAD_INTEGRITY)
             goto cleanup;
         ret = 0;
+        if (elements == NULL)
+            continue;
 
         /* Add the verified elements to list and free the container array. */
         for (n_elements = 0; elements[n_elements] != NULL; n_elements++);