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llc: Check netns in llc_estab_match() and llc_listener_match().

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We will remove this restriction in llc_rcv() in the following patch,
which means that the protocol handler must be aware of netns.

        if (!net_eq(dev_net(dev), &init_net))
                goto drop;

llc_rcv() fetches llc_type_handlers[llc_pdu_type(skb) - 1] and calls it
if not NULL.

If the PDU type is LLC_DEST_CONN, llc_conn_handler() is called to pass
skb to corresponding sockets.  Then, we must look up a proper socket in
the same netns with skb->dev.

llc_conn_handler() calls __llc_lookup() to look up a established or
litening socket by __llc_lookup_established() and llc_lookup_listener().

Both functions iterate on a list and call llc_estab_match() or
llc_listener_match() to check if the socket is the correct destination.
However, these functions do not check netns.

Also, bind() and connect() call llc_establish_connection(), which
finally calls __llc_lookup_established(), to check if there is a
conflicting socket.

Let's test netns in llc_estab_match() and llc_listener_match().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Kuniyuki Iwashima 2023-07-18 10:41:50 -07:00 committed by Paolo Abeni
parent 9b64e93e83
commit 97b1d320f4
4 changed files with 33 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/net/llc_conn.h
View File

@ -111,7 +111,7 @@ void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit);
void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit);
int llc_conn_remove_acked_pdus(struct sock *conn, u8 nr, u16 *how_many_unacked);
struct sock *llc_lookup_established(struct llc_sap *sap, struct llc_addr *daddr,
struct llc_addr *laddr);
struct llc_addr *laddr, const struct net *net);
void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk);
void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk);

2
net/llc/af_llc.c
View File

@ -402,7 +402,7 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
laddr.lsap = addr->sllc_sap;
rc = -EADDRINUSE; /* mac + sap clash. */
ask = llc_lookup_established(sap, &daddr, &laddr);
ask = llc_lookup_established(sap, &daddr, &laddr, &init_net);
if (ask) {
sock_put(ask);
goto out_put;

49
net/llc/llc_conn.c
View File

@ -453,11 +453,13 @@ static int llc_exec_conn_trans_actions(struct sock *sk,
static inline bool llc_estab_match(const struct llc_sap *sap,
const struct llc_addr *daddr,
const struct llc_addr *laddr,
const struct sock *sk)
const struct sock *sk,
const struct net *net)
{
struct llc_sock *llc = llc_sk(sk);
return llc->laddr.lsap == laddr->lsap &&
return net_eq(sock_net(sk), net) &&
llc->laddr.lsap == laddr->lsap &&
llc->daddr.lsap == daddr->lsap &&
ether_addr_equal(llc->laddr.mac, laddr->mac) &&
ether_addr_equal(llc->daddr.mac, daddr->mac);
@ -468,6 +470,7 @@ static inline bool llc_estab_match(const struct llc_sap *sap,
* @sap: SAP
* @daddr: address of remote LLC (MAC + SAP)
* @laddr: address of local LLC (MAC + SAP)
* @net: netns to look up a socket in
*
* Search connection list of the SAP and finds connection using the remote
* mac, remote sap, local mac, and local sap. Returns pointer for
@ -476,7 +479,8 @@ static inline bool llc_estab_match(const struct llc_sap *sap,
*/
static struct sock *__llc_lookup_established(struct llc_sap *sap,
struct llc_addr *daddr,
struct llc_addr *laddr)
struct llc_addr *laddr,
const struct net *net)
{
struct sock *rc;
struct hlist_nulls_node *node;
@ -486,12 +490,12 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
rcu_read_lock();
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_estab_match(sap, daddr, laddr, rc)) {
if (llc_estab_match(sap, daddr, laddr, rc, net)) {
/* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!refcount_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
!llc_estab_match(sap, daddr, laddr, rc))) {
!llc_estab_match(sap, daddr, laddr, rc, net))) {
sock_put(rc);
continue;
}
@ -513,29 +517,33 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
struct sock *llc_lookup_established(struct llc_sap *sap,
struct llc_addr *daddr,
struct llc_addr *laddr)
struct llc_addr *laddr,
const struct net *net)
{
struct sock *sk;
local_bh_disable();
sk = __llc_lookup_established(sap, daddr, laddr);
sk = __llc_lookup_established(sap, daddr, laddr, net);
local_bh_enable();
return sk;
}
static inline bool llc_listener_match(const struct llc_sap *sap,
const struct llc_addr *laddr,
const struct sock *sk)
const struct sock *sk,
const struct net *net)
{
struct llc_sock *llc = llc_sk(sk);
return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
return net_eq(sock_net(sk), net) &&
sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
llc->laddr.lsap == laddr->lsap &&
ether_addr_equal(llc->laddr.mac, laddr->mac);
}
static struct sock *__llc_lookup_listener(struct llc_sap *sap,
struct llc_addr *laddr)
struct llc_addr *laddr,
const struct net *net)
{
struct sock *rc;
struct hlist_nulls_node *node;
@ -545,12 +553,12 @@ static struct sock *__llc_lookup_listener(struct llc_sap *sap,
rcu_read_lock();
again:
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
if (llc_listener_match(sap, laddr, rc)) {
if (llc_listener_match(sap, laddr, rc, net)) {
/* Extra checks required by SLAB_TYPESAFE_BY_RCU */
if (unlikely(!refcount_inc_not_zero(&rc->sk_refcnt)))
goto again;
if (unlikely(llc_sk(rc)->sap != sap ||
!llc_listener_match(sap, laddr, rc))) {
!llc_listener_match(sap, laddr, rc, net))) {
sock_put(rc);
continue;
}
@ -574,6 +582,7 @@ static struct sock *__llc_lookup_listener(struct llc_sap *sap,
* llc_lookup_listener - Finds listener for local MAC + SAP
* @sap: SAP
* @laddr: address of local LLC (MAC + SAP)
* @net: netns to look up a socket in
*
* Search connection list of the SAP and finds connection listening on
* local mac, and local sap. Returns pointer for parent socket found,
@ -581,24 +590,26 @@ static struct sock *__llc_lookup_listener(struct llc_sap *sap,
* Caller has to make sure local_bh is disabled.
*/
static struct sock *llc_lookup_listener(struct llc_sap *sap,
struct llc_addr *laddr)
struct llc_addr *laddr,
const struct net *net)
{
struct sock *rc = __llc_lookup_listener(sap, laddr, net);
static struct llc_addr null_addr;
struct sock *rc = __llc_lookup_listener(sap, laddr);
if (!rc)
rc = __llc_lookup_listener(sap, &null_addr);
rc = __llc_lookup_listener(sap, &null_addr, net);
return rc;
}
static struct sock *__llc_lookup(struct llc_sap *sap,
struct llc_addr *daddr,
struct llc_addr *laddr)
struct llc_addr *laddr,
const struct net *net)
{
struct sock *sk = __llc_lookup_established(sap, daddr, laddr);
struct sock *sk = __llc_lookup_established(sap, daddr, laddr, net);
return sk ? : llc_lookup_listener(sap, laddr);
return sk ? : llc_lookup_listener(sap, laddr, net);
}
/**
@ -776,7 +787,7 @@ void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb)
llc_pdu_decode_da(skb, daddr.mac);
llc_pdu_decode_dsap(skb, &daddr.lsap);
sk = __llc_lookup(sap, &saddr, &daddr);
sk = __llc_lookup(sap, &saddr, &daddr, dev_net(skb->dev));
if (!sk)
goto drop;

2
net/llc/llc_if.c
View File

@ -92,7 +92,7 @@ int llc_establish_connection(struct sock *sk, const u8 *lmac, u8 *dmac, u8 dsap)
daddr.lsap = dsap;
memcpy(daddr.mac, dmac, sizeof(daddr.mac));
memcpy(laddr.mac, lmac, sizeof(laddr.mac));
existing = llc_lookup_established(llc->sap, &daddr, &laddr);
existing = llc_lookup_established(llc->sap, &daddr, &laddr, sock_net(sk));
if (existing) {
if (existing->sk_state == TCP_ESTABLISHED) {
sk = existing;