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llc: fix another potential sk_buff leak in llc_ui_sendmsg()

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All callers of llc_conn_state_process() except llc_build_and_send_pkt()
(via llc_ui_sendmsg() -> llc_ui_send_data()) assume that it always
consumes a reference to the skb.  Fix this caller to do the same.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
This commit is contained in:
Eric Biggers 2019-10-06 14:24:26 -07:00 committed by Jakub Kicinski
parent b74555de21
commit fc8d5db10c
3 changed files with 30 additions and 18 deletions
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34
net/llc/af_llc.c
View File

@ -113,22 +113,26 @@ static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
*
* Send data via reliable llc2 connection.
* Returns 0 upon success, non-zero if action did not succeed.
*
* This function always consumes a reference to the skb.
*/
static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
{
struct llc_sock* llc = llc_sk(sk);
int rc = 0;
if (unlikely(llc_data_accept_state(llc->state) ||
llc->remote_busy_flag ||
llc->p_flag)) {
long timeout = sock_sndtimeo(sk, noblock);
int rc;
rc = llc_ui_wait_for_busy_core(sk, timeout);
if (rc) {
kfree_skb(skb);
return rc;
}
}
if (unlikely(!rc))
rc = llc_build_and_send_pkt(sk, skb);
return rc;
return llc_build_and_send_pkt(sk, skb);
}
static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
@ -899,7 +903,7 @@ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
int flags = msg->msg_flags;
int noblock = flags & MSG_DONTWAIT;
struct sk_buff *skb;
struct sk_buff *skb = NULL;
size_t size = 0;
int rc = -EINVAL, copied = 0, hdrlen;
@ -908,10 +912,10 @@ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
lock_sock(sk);
if (addr) {
if (msg->msg_namelen < sizeof(*addr))
goto release;
goto out;
} else {
if (llc_ui_addr_null(&llc->addr))
goto release;
goto out;
addr = &llc->addr;
}
/* must bind connection to sap if user hasn't done it. */
@ -919,7 +923,7 @@ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
/* bind to sap with null dev, exclusive. */
rc = llc_ui_autobind(sock, addr);
if (rc)
goto release;
goto out;
}
hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
size = hdrlen + len;
@ -928,12 +932,12 @@ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
copied = size - hdrlen;
rc = -EINVAL;
if (copied < 0)
goto release;
goto out;
release_sock(sk);
skb = sock_alloc_send_skb(sk, size, noblock, &rc);
lock_sock(sk);
if (!skb)
goto release;
goto out;
skb->dev = llc->dev;
skb->protocol = llc_proto_type(addr->sllc_arphrd);
skb_reserve(skb, hdrlen);
@ -943,29 +947,31 @@ static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
addr->sllc_sap);
skb = NULL;
goto out;
}
if (addr->sllc_test) {
llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
addr->sllc_sap);
skb = NULL;
goto out;
}
if (addr->sllc_xid) {
llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
addr->sllc_sap);
skb = NULL;
goto out;
}
rc = -ENOPROTOOPT;
if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
goto out;
rc = llc_ui_send_data(sk, skb, noblock);
skb = NULL;
out:
if (rc) {
kfree_skb(skb);
release:
kfree_skb(skb);
if (rc)
dprintk("%s: failed sending from %02X to %02X: %d\n",
__func__, llc->laddr.lsap, llc->daddr.lsap, rc);
}
release_sock(sk);
return rc ? : copied;
}

2
net/llc/llc_conn.c
View File

@ -55,6 +55,8 @@ int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ;
* (executing it's actions and changing state), upper layer will be
* indicated or confirmed, if needed. Returns 0 for success, 1 for
* failure. The socket lock has to be held before calling this function.
*
* This function always consumes a reference to the skb.
*/
int llc_conn_state_process(struct sock *sk, struct sk_buff *skb)
{

12
net/llc/llc_if.c
View File

@ -38,6 +38,8 @@
* closed and -EBUSY when sending data is not permitted in this state or
* LLC has send an I pdu with p bit set to 1 and is waiting for it's
* response.
*
* This function always consumes a reference to the skb.
*/
int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb)
{
@ -46,20 +48,22 @@ int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb)
struct llc_sock *llc = llc_sk(sk);
if (unlikely(llc->state == LLC_CONN_STATE_ADM))
goto out;
goto out_free;
rc = -EBUSY;
if (unlikely(llc_data_accept_state(llc->state) || /* data_conn_refuse */
llc->p_flag)) {
llc->failed_data_req = 1;
goto out;
goto out_free;
}
ev = llc_conn_ev(skb);
ev->type = LLC_CONN_EV_TYPE_PRIM;
ev->prim = LLC_DATA_PRIM;
ev->prim_type = LLC_PRIM_TYPE_REQ;
skb->dev = llc->dev;
rc = llc_conn_state_process(sk, skb);
out:
return llc_conn_state_process(sk, skb);
out_free:
kfree_skb(skb);
return rc;
}