s4:auth: Check that the PAC is not NULL before dereferencing it

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/auth/kerberos/kerberos_pac.c b/source4/auth/kerberos/kerberos_pac.c
index 4f291d81064193320f2467cea1ca3c6e14737cd3..c33dc2f9217d61b0c9db63d4c0b27d5309f78704 100644 (file)
--- a/source4/auth/kerberos/kerberos_pac.c
+++ b/source4/auth/kerberos/kerberos_pac.c
@@ -337,6 +337,11 @@ krb5_error_code kerberos_pac_to_user_info_dc(TALLOC_CTX *mem_ctx,
                return ENOMEM;
        }
 
+       if (pac == NULL) {
+               talloc_free(tmp_ctx);
+               return EINVAL;
+       }
+
        ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_LOGON_INFO, &k5pac_logon_info_in);
        if (ret != 0) {
                talloc_free(tmp_ctx);