[PATCH net v6 09/10] rxrpc: Fix CHALLENGE packet overqueuing and simplify RESPONSE generation

@@ -78,6 +78,7 @@
 	EM(rxgk_abort_2_short_encdata,		"rxgk2-short-encdata")	\
 	EM(rxgk_abort_2_short_header,		"rxgk2-short-hdr")	\
 	EM(rxgk_abort_bad_key_number,		"rxgk-bad-key-num")	\
+	EM(rxgk_abort_chall_bad_app_key,	"rxgk-chall-bad-app-key")\
 	EM(rxgk_abort_chall_key_expired,	"rxgk-chall-key-exp")	\
 	EM(rxgk_abort_chall_no_key,		"rxgk-chall-nokey")	\
 	EM(rxgk_abort_chall_short,		"rxgk-chall-short")	\

@@ -598,10 +598,7 @@ static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
 		fallthrough;
 	case RXRPC_SERVER_BOUND:
 	case RXRPC_SERVER_LISTENING:
-		if (m->msg_flags & MSG_OOB)
-			ret = rxrpc_sendmsg_oob(rx, m, len);
-		else
-			ret = rxrpc_do_sendmsg(rx, m, len);
+		ret = rxrpc_do_sendmsg(rx, m, len);
 		/* The socket has been unlocked */
 		goto out;
 	default:

@@ -279,10 +279,7 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
 
 	switch (sp->hdr.type) {
 	case RXRPC_PACKET_TYPE_CHALLENGE:
-		ret = conn->security->respond_to_challenge(conn, skb);
-		sp->chall.conn = NULL;
-		rxrpc_put_connection(conn, rxrpc_conn_put_challenge_input);
-		return ret;
+		return conn->security->respond_to_challenge(conn, skb);
 
 	case RXRPC_PACKET_TYPE_RESPONSE:
 		spin_lock_irq(&conn->state_lock);

@@ -425,66 +422,6 @@ static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
 	rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
 }
 
-/*
- * Post a CHALLENGE packet to the socket of one of a connection's calls so that
- * it can get application data to include in the packet, possibly querying
- * userspace.
- */
-static bool rxrpc_post_challenge(struct rxrpc_connection *conn,
-				 struct sk_buff *skb)
-{
-	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-	struct rxrpc_call *call = NULL;
-	struct rxrpc_sock *rx;
-	bool respond = false, queued = false;
-
-	sp->chall.conn =
-		rxrpc_get_connection(conn, rxrpc_conn_get_challenge_input);
-
-	if (!conn->security->challenge_to_recvmsg) {
-		rxrpc_post_packet_to_conn(conn, skb);
-		return true;
-	}
-
-	rcu_read_lock();
-
-	for (int i = 0; i < ARRAY_SIZE(conn->channels); i++) {
-		if (conn->channels[i].call) {
-			call = conn->channels[i].call;
-			rx = rcu_dereference(call->socket);
-			if (!rx) {
-				call = NULL;
-				continue;
-			}
-
-			respond = true;
-			if (test_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags))
-				break;
-			call = NULL;
-		}
-	}
-
-	if (!respond) {
-		rcu_read_unlock();
-		rxrpc_put_connection(conn, rxrpc_conn_put_challenge_input);
-		sp->chall.conn = NULL;
-		return false;
-	}
-
-	if (call)
-		queued = rxrpc_notify_socket_oob(call, skb);
-	rcu_read_unlock();
-	if (call && !queued) {
-		rxrpc_put_connection(conn, rxrpc_conn_put_challenge_input);
-		sp->chall.conn = NULL;
-		return false;
-	}
-
-	if (!call)
-		rxrpc_post_packet_to_conn(conn, skb);
-	return true;
-}
-
 /*
  * Input a connection-level packet.
  */

@@ -513,7 +450,8 @@ bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
 		}
 		if (!conn->security->validate_challenge(conn, skb))
 			return false;
-		return rxrpc_post_challenge(conn, skb);
+		rxrpc_post_packet_to_conn(conn, skb);
+		return true;
 
 	case RXRPC_PACKET_TYPE_RESPONSE:
 		if (rxrpc_is_conn_aborted(conn)) {

@@ -11,6 +11,7 @@
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/key-type.h>
+#include <keys/user-type.h>
 #include "ar-internal.h"
 #include "rxgk_common.h"
 

@@ -837,7 +838,7 @@ static noinline ssize_t rxgk_insert_response_header(struct rxrpc_connection *con
  */
 static ssize_t rxgk_construct_authenticator(struct rxrpc_connection *conn,
 					    struct sk_buff *challenge,
-					    const struct krb5_buffer *appdata,
+					    const struct user_key_payload *appdata,
 					    struct sk_buff *response,
 					    size_t offset)
 {

@@ -859,20 +860,20 @@ static ssize_t rxgk_construct_authenticator(struct rxrpc_connection *conn,
 	if (ret < 0)
 		return -EPROTO;
 
-	a.appdata_len = htonl(appdata->len);
+	a.appdata_len = htonl(appdata->datalen);
 
 	ret = skb_store_bits(response, offset, &a, sizeof(a));
 	if (ret < 0)
 		return ret;
 	offset += sizeof(a);
 
-	if (appdata->len) {
-		ret = skb_store_bits(response, offset, appdata->data, appdata->len);
+	if (appdata->datalen) {
+		ret = skb_store_bits(response, offset, appdata->data, appdata->datalen);
 		if (ret < 0)
 			return ret;
-		offset += appdata->len;
+		offset += appdata->datalen;
 
-		ret = rxgk_pad_out(response, appdata->len, offset);
+		ret = rxgk_pad_out(response, appdata->datalen, offset);
 		if (ret < 0)
 			return ret;
 		offset += ret;

@@ -890,7 +891,7 @@ static ssize_t rxgk_construct_authenticator(struct rxrpc_connection *conn,
 	ret = skb_store_bits(response, offset, &b, sizeof(b));
 	if (ret < 0)
 		return ret;
-	return sizeof(a) + xdr_round_up(appdata->len) + sizeof(b);
+	return sizeof(a) + xdr_round_up(appdata->datalen) + sizeof(b);
 }
 
 static ssize_t rxgk_encrypt_authenticator(struct rxrpc_connection *conn,

@@ -923,7 +924,7 @@ static ssize_t rxgk_encrypt_authenticator(struct rxrpc_connection *conn,
  */
 static int rxgk_construct_response(struct rxrpc_connection *conn,
 				   struct sk_buff *challenge,
-				   struct krb5_buffer *appdata)
+				   const struct user_key_payload *appdata)
 {
 	struct rxrpc_skb_priv *csp, *rsp;
 	struct rxgk_context *gk;

@@ -936,11 +937,11 @@ static int rxgk_construct_response(struct rxrpc_connection *conn,
 	if (IS_ERR(gk))
 		return PTR_ERR(gk);
 
-	auth_len = 20 + (4 + appdata->len) + 12 + (1 + 4) * 4;
+	auth_len = 20 + xdr_object_len(appdata->datalen) + 12 + (1 + 4) * 4;
 	authx_len = crypto_krb5_how_much_buffer(gk->krb5, KRB5_ENCRYPT_MODE,
 						auth_len, &auth_offset);
 	len = sizeof(struct rxrpc_wire_header) +
-		8 + (4 + xdr_round_up(gk->key->ticket.len)) + (4 + authx_len);
+		8 + xdr_object_len(gk->key->ticket.len) + xdr_object_len(authx_len);
 
 	response = alloc_skb_with_frags(0, len, 0, &ret, GFP_NOFS);
 	if (!response)

@@ -1011,24 +1012,44 @@ static int rxgk_construct_response(struct rxrpc_connection *conn,
  * Respond to a challenge packet.
  */
 static int rxgk_respond_to_challenge(struct rxrpc_connection *conn,
-				     struct sk_buff *challenge,
-				     struct krb5_buffer *appdata)
+				     struct sk_buff *challenge)
 {
-	_enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
+	struct user_key_payload dummy = {}, *appdata = &dummy;
+	int ret;
+
+	_enter("{%d,%u,%x,%x}",
+	       conn->debug_id, conn->service_id,
+	       key_serial(conn->key), key_serial(conn->bundle->app_data));
 
 	if (key_validate(conn->key) < 0)
 		return rxrpc_abort_conn(conn, NULL, RXGK_EXPIRED, -EPROTO,
 					rxgk_abort_chall_key_expired);
 
-	return rxgk_construct_response(conn, challenge, appdata);
-}
+	if (conn->bundle->app_data) {
+		struct key *app_key = conn->bundle->app_data;
+
+		/* The wrong sort of key shouldn't get this far. */
+		if (WARN_ON_ONCE(app_key->type != &key_type_user &&
+				 app_key->type != &key_type_logon))
+			return rxrpc_abort_conn(conn, NULL, RXGK_EXPIRED, -EKEYREJECTED,
+						rxgk_abort_chall_bad_app_key);
+
+		rcu_read_lock();
+		appdata = (struct user_key_payload *)
+			user_key_payload_rcu(conn->bundle->app_data);
+		if (appdata && !refcount_inc_not_zero(&appdata->ref))
+			appdata = NULL;
+		rcu_read_unlock();
+		if (!appdata)
+			return rxrpc_abort_conn(conn, NULL, RXGK_EXPIRED, -EKEYREVOKED,
+						rxgk_abort_chall_key_expired);
+	}
 
-static int rxgk_respond_to_challenge_no_appdata(struct rxrpc_connection *conn,
-						struct sk_buff *challenge)
-{
-	struct krb5_buffer appdata = {};
+	ret = rxgk_construct_response(conn, challenge, appdata);
 
-	return rxgk_respond_to_challenge(conn, challenge, &appdata);
+	if (appdata != &dummy)
+		put_user_key_payload(appdata);
+	return ret;
 }
 
 /**

@@ -1044,9 +1065,7 @@ static int rxgk_respond_to_challenge_no_appdata(struct rxrpc_connection *conn,
 int rxgk_kernel_respond_to_challenge(struct sk_buff *challenge,
 				     struct krb5_buffer *appdata)
 {
-	struct rxrpc_skb_priv *csp = rxrpc_skb(challenge);
-
-	return rxgk_respond_to_challenge(csp->chall.conn, challenge, appdata);
+	return -EINVAL;
 }
 EXPORT_SYMBOL(rxgk_kernel_respond_to_challenge);
 

@@ -1348,7 +1367,7 @@ const struct rxrpc_security rxgk_yfs = {
 	.validate_challenge		= rxgk_validate_challenge,
 	.challenge_to_recvmsg		= rxgk_challenge_to_recvmsg,
 	.sendmsg_respond_to_challenge	= rxgk_sendmsg_respond_to_challenge,
-	.respond_to_challenge		= rxgk_respond_to_challenge_no_appdata,
+	.respond_to_challenge		= rxgk_respond_to_challenge,
 	.verify_response		= rxgk_verify_response,
 	.clear				= rxgk_clear,
 	.default_decode_ticket		= rxgk_yfs_decode_ticket,