sunrpc: GSS integrity and decryption failures should return GARBAGE_ARGS

In function svcauth_gss_accept() (net/sunrpc/auth_gss/svcauth_gss.c) the
code that handles GSS integrity and decryption failures should be
returning GARBAGE_ARGS as specified in RFC 2203, sections 5.3.3.4.2 and
5.3.3.4.3.

Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: Harshula Jayasuriya <harshula@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

net/sunrpc/auth_gss/svcauth_gss.c

@@ -1146,7 +1146,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 		case RPC_GSS_SVC_INTEGRITY:
 			if (unwrap_integ_data(&rqstp->rq_arg,
 					gc->gc_seq, rsci->mechctx))
-				goto auth_err;
+				goto garbage_args;
 			/* placeholders for length and seq. number: */
 			svc_putnl(resv, 0);
 			svc_putnl(resv, 0);
@@ -1154,7 +1154,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 		case RPC_GSS_SVC_PRIVACY:
 			if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
 					gc->gc_seq, rsci->mechctx))
-				goto auth_err;
+				goto garbage_args;
 			/* placeholders for length and seq. number: */
 			svc_putnl(resv, 0);
 			svc_putnl(resv, 0);
@@ -1169,6 +1169,11 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 		ret = SVC_OK;
 		goto out;
 	}
+garbage_args:
+	/* Restore write pointer to its original value: */
+	xdr_ressize_check(rqstp, reject_stat);
+	ret = SVC_GARBAGE;
+	goto out;
 auth_err:
 	/* Restore write pointer to its original value: */
 	xdr_ressize_check(rqstp, reject_stat);

net/sunrpc/svc.c

@@ -921,8 +921,7 @@ svc_process(struct svc_rqst *rqstp)
 	case SVC_OK:
 		break;
 	case SVC_GARBAGE:
-		rpc_stat = rpc_garbage_args;
-		goto err_bad;
+		goto err_garbage;
 	case SVC_SYSERR:
 		rpc_stat = rpc_system_err;
 		goto err_bad;