Fix memory leak in OTP kdcpreauth module

In otp_edata(), free the generated nonce.

ticket: 9063 (new)
tags: pullup
target_version: 1.20-next
target_version: 1.19-next

src/plugins/preauth/otp/main.c

@@ -228,7 +228,7 @@ otp_edata(krb5_context context, krb5_kdc_req *request,
     krb5_pa_otp_challenge chl;
     krb5_pa_data *pa = NULL;
     krb5_error_code retval;
-    krb5_data *encoding;
+    krb5_data *encoding, nonce = empty_data();
     char *config;
 
     /* Determine if otp is enabled for the user. */
@@ -256,9 +256,10 @@ otp_edata(krb5_context context, krb5_kdc_req *request,
     ti.iteration_count = -1;
 
     /* Generate the nonce. */
-    retval = nonce_generate(context, armor_key->length, &chl.nonce);
+    retval = nonce_generate(context, armor_key->length, &nonce);
     if (retval != 0)
         goto out;
+    chl.nonce = nonce;
 
     /* Build the output pa-data. */
     retval = encode_krb5_pa_otp_challenge(&chl, &encoding);
@@ -275,6 +276,7 @@ otp_edata(krb5_context context, krb5_kdc_req *request,
     free(encoding);
 
 out:
+    krb5_free_data_contents(context, &nonce);
     (*respond)(arg, retval, pa);
 }