linux/net/rxrpc/security.c
David Howells 063c60d391 rxrpc: Fix missing security check on incoming calls
Fix rxrpc_new_incoming_call() to check that we have a suitable service key
available for the combination of service ID and security class of a new
incoming call - and to reject calls for which we don't.

This causes an assertion like the following to appear:

	rxrpc: Assertion failed - 6(0x6) == 12(0xc) is false
	kernel BUG at net/rxrpc/call_object.c:456!

Where call->state is RXRPC_CALL_SERVER_SECURING (6) rather than
RXRPC_CALL_COMPLETE (12).

Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2019-12-20 16:21:32 +00:00

159 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC security handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <linux/crypto.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <keys/rxrpc-type.h>
#include "ar-internal.h"
static const struct rxrpc_security *rxrpc_security_types[] = {
[RXRPC_SECURITY_NONE] = &rxrpc_no_security,
#ifdef CONFIG_RXKAD
[RXRPC_SECURITY_RXKAD] = &rxkad,
#endif
};
int __init rxrpc_init_security(void)
{
int i, ret;
for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
if (rxrpc_security_types[i]) {
ret = rxrpc_security_types[i]->init();
if (ret < 0)
goto failed;
}
}
return 0;
failed:
for (i--; i >= 0; i--)
if (rxrpc_security_types[i])
rxrpc_security_types[i]->exit();
return ret;
}
void rxrpc_exit_security(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
if (rxrpc_security_types[i])
rxrpc_security_types[i]->exit();
}
/*
* look up an rxrpc security module
*/
static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
{
if (security_index >= ARRAY_SIZE(rxrpc_security_types))
return NULL;
return rxrpc_security_types[security_index];
}
/*
* initialise the security on a client connection
*/
int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
{
const struct rxrpc_security *sec;
struct rxrpc_key_token *token;
struct key *key = conn->params.key;
int ret;
_enter("{%d},{%x}", conn->debug_id, key_serial(key));
if (!key)
return 0;
ret = key_validate(key);
if (ret < 0)
return ret;
token = key->payload.data[0];
if (!token)
return -EKEYREJECTED;
sec = rxrpc_security_lookup(token->security_index);
if (!sec)
return -EKEYREJECTED;
conn->security = sec;
ret = conn->security->init_connection_security(conn);
if (ret < 0) {
conn->security = &rxrpc_no_security;
return ret;
}
_leave(" = 0");
return 0;
}
/*
* Find the security key for a server connection.
*/
bool rxrpc_look_up_server_security(struct rxrpc_local *local, struct rxrpc_sock *rx,
const struct rxrpc_security **_sec,
struct key **_key,
struct sk_buff *skb)
{
const struct rxrpc_security *sec;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
key_ref_t kref = NULL;
char kdesc[5 + 1 + 3 + 1];
_enter("");
sprintf(kdesc, "%u:%u", sp->hdr.serviceId, sp->hdr.securityIndex);
sec = rxrpc_security_lookup(sp->hdr.securityIndex);
if (!sec) {
trace_rxrpc_abort(0, "SVS",
sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_INVALID_OPERATION, EKEYREJECTED);
skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
skb->priority = RX_INVALID_OPERATION;
return false;
}
if (sp->hdr.securityIndex == RXRPC_SECURITY_NONE)
goto out;
if (!rx->securities) {
trace_rxrpc_abort(0, "SVR",
sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_INVALID_OPERATION, EKEYREJECTED);
skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
skb->priority = RX_INVALID_OPERATION;
return false;
}
/* look through the service's keyring */
kref = keyring_search(make_key_ref(rx->securities, 1UL),
&key_type_rxrpc_s, kdesc, true);
if (IS_ERR(kref)) {
trace_rxrpc_abort(0, "SVK",
sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
sec->no_key_abort, EKEYREJECTED);
skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
skb->priority = sec->no_key_abort;
return false;
}
out:
*_sec = sec;
*_key = key_ref_to_ptr(kref);
return true;
}