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authorDavid S. Miller <davem@davemloft.net>2019-11-13 11:47:02 -0800
committerDavid S. Miller <davem@davemloft.net>2019-11-13 11:47:02 -0800
commitb3dff0eb4b98c16e7dc395326425569e226f7843 (patch)
tree39021f7475aa67c61e2827372895404faad92560 /net
parentc3afb7eab0b3703d77ab3c569fda698ece16a717 (diff)
parent4a15d574e68afffbe8d7265e015cda2ac2a248ec (diff)
Merge tag 'linux-can-fixes-for-5.4-20191113' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says: ==================== pull-request: can 2019-11-13 this is a pull request of 9 patches for net/master, hopefully for the v5.4 release cycle. All nine patches are by Oleksij Rempel and fix locking and use-after-free bugs in the j1939 stack found by the syzkaller syzbot. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/can/af_can.c3
-rw-r--r--net/can/j1939/main.c9
-rw-r--r--net/can/j1939/socket.c94
-rw-r--r--net/can/j1939/transport.c36
4 files changed, 112 insertions, 30 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 5518a7d9eed9..128d37a4c2e0 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -86,11 +86,12 @@ static atomic_t skbcounter = ATOMIC_INIT(0);
/* af_can socket functions */
-static void can_sock_destruct(struct sock *sk)
+void can_sock_destruct(struct sock *sk)
{
skb_queue_purge(&sk->sk_receive_queue);
skb_queue_purge(&sk->sk_error_queue);
}
+EXPORT_SYMBOL(can_sock_destruct);
static const struct can_proto *can_get_proto(int protocol)
{
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index def2f813ffce..137054bff9ec 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -51,6 +51,7 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
if (!skb)
return;
+ j1939_priv_get(priv);
can_skb_set_owner(skb, iskb->sk);
/* get a pointer to the header of the skb
@@ -104,6 +105,7 @@ static void j1939_can_recv(struct sk_buff *iskb, void *data)
j1939_simple_recv(priv, skb);
j1939_sk_recv(priv, skb);
done:
+ j1939_priv_put(priv);
kfree_skb(skb);
}
@@ -150,6 +152,10 @@ static void __j1939_priv_release(struct kref *kref)
netdev_dbg(priv->ndev, "%s: 0x%p\n", __func__, priv);
+ WARN_ON_ONCE(!list_empty(&priv->active_session_list));
+ WARN_ON_ONCE(!list_empty(&priv->ecus));
+ WARN_ON_ONCE(!list_empty(&priv->j1939_socks));
+
dev_put(ndev);
kfree(priv);
}
@@ -207,6 +213,9 @@ static inline struct j1939_priv *j1939_ndev_to_priv(struct net_device *ndev)
{
struct can_ml_priv *can_ml_priv = ndev->ml_priv;
+ if (!can_ml_priv)
+ return NULL;
+
return can_ml_priv->j1939_priv;
}
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index 4d8ba701e15d..de09b0a65791 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -78,7 +78,6 @@ static void j1939_jsk_add(struct j1939_priv *priv, struct j1939_sock *jsk)
{
jsk->state |= J1939_SOCK_BOUND;
j1939_priv_get(priv);
- jsk->priv = priv;
spin_lock_bh(&priv->j1939_socks_lock);
list_add_tail(&jsk->list, &priv->j1939_socks);
@@ -91,7 +90,6 @@ static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
list_del_init(&jsk->list);
spin_unlock_bh(&priv->j1939_socks_lock);
- jsk->priv = NULL;
j1939_priv_put(priv);
jsk->state &= ~J1939_SOCK_BOUND;
}
@@ -349,6 +347,34 @@ void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
spin_unlock_bh(&priv->j1939_socks_lock);
}
+static void j1939_sk_sock_destruct(struct sock *sk)
+{
+ struct j1939_sock *jsk = j1939_sk(sk);
+
+ /* This function will be call by the generic networking code, when then
+ * the socket is ultimately closed (sk->sk_destruct).
+ *
+ * The race between
+ * - processing a received CAN frame
+ * (can_receive -> j1939_can_recv)
+ * and accessing j1939_priv
+ * ... and ...
+ * - closing a socket
+ * (j1939_can_rx_unregister -> can_rx_unregister)
+ * and calling the final j1939_priv_put()
+ *
+ * is avoided by calling the final j1939_priv_put() from this
+ * RCU deferred cleanup call.
+ */
+ if (jsk->priv) {
+ j1939_priv_put(jsk->priv);
+ jsk->priv = NULL;
+ }
+
+ /* call generic CAN sock destruct */
+ can_sock_destruct(sk);
+}
+
static int j1939_sk_init(struct sock *sk)
{
struct j1939_sock *jsk = j1939_sk(sk);
@@ -371,6 +397,7 @@ static int j1939_sk_init(struct sock *sk)
atomic_set(&jsk->skb_pending, 0);
spin_lock_init(&jsk->sk_session_queue_lock);
INIT_LIST_HEAD(&jsk->sk_session_queue);
+ sk->sk_destruct = j1939_sk_sock_destruct;
return 0;
}
@@ -443,6 +470,12 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
}
jsk->ifindex = addr->can_ifindex;
+
+ /* the corresponding j1939_priv_put() is called via
+ * sk->sk_destruct, which points to j1939_sk_sock_destruct()
+ */
+ j1939_priv_get(priv);
+ jsk->priv = priv;
}
/* set default transmit pgn */
@@ -560,8 +593,8 @@ static int j1939_sk_release(struct socket *sock)
if (!sk)
return 0;
- jsk = j1939_sk(sk);
lock_sock(sk);
+ jsk = j1939_sk(sk);
if (jsk->state & J1939_SOCK_BOUND) {
struct j1939_priv *priv = jsk->priv;
@@ -1059,51 +1092,72 @@ static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
{
struct sock *sk = sock->sk;
struct j1939_sock *jsk = j1939_sk(sk);
- struct j1939_priv *priv = jsk->priv;
+ struct j1939_priv *priv;
int ifindex;
int ret;
+ lock_sock(sock->sk);
/* various socket state tests */
- if (!(jsk->state & J1939_SOCK_BOUND))
- return -EBADFD;
+ if (!(jsk->state & J1939_SOCK_BOUND)) {
+ ret = -EBADFD;
+ goto sendmsg_done;
+ }
+ priv = jsk->priv;
ifindex = jsk->ifindex;
- if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR)
+ if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR) {
/* no source address assigned yet */
- return -EBADFD;
+ ret = -EBADFD;
+ goto sendmsg_done;
+ }
/* deal with provided destination address info */
if (msg->msg_name) {
struct sockaddr_can *addr = msg->msg_name;
- if (msg->msg_namelen < J1939_MIN_NAMELEN)
- return -EINVAL;
+ if (msg->msg_namelen < J1939_MIN_NAMELEN) {
+ ret = -EINVAL;
+ goto sendmsg_done;
+ }
- if (addr->can_family != AF_CAN)
- return -EINVAL;
+ if (addr->can_family != AF_CAN) {
+ ret = -EINVAL;
+ goto sendmsg_done;
+ }
- if (addr->can_ifindex && addr->can_ifindex != ifindex)
- return -EBADFD;
+ if (addr->can_ifindex && addr->can_ifindex != ifindex) {
+ ret = -EBADFD;
+ goto sendmsg_done;
+ }
if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
- !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
- return -EINVAL;
+ !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn)) {
+ ret = -EINVAL;
+ goto sendmsg_done;
+ }
if (!addr->can_addr.j1939.name &&
addr->can_addr.j1939.addr == J1939_NO_ADDR &&
- !sock_flag(sk, SOCK_BROADCAST))
+ !sock_flag(sk, SOCK_BROADCAST)) {
/* broadcast, but SO_BROADCAST not set */
- return -EACCES;
+ ret = -EACCES;
+ goto sendmsg_done;
+ }
} else {
if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
- !sock_flag(sk, SOCK_BROADCAST))
+ !sock_flag(sk, SOCK_BROADCAST)) {
/* broadcast, but SO_BROADCAST not set */
- return -EACCES;
+ ret = -EACCES;
+ goto sendmsg_done;
+ }
}
ret = j1939_sk_send_loop(priv, sk, msg, size);
+sendmsg_done:
+ release_sock(sock->sk);
+
return ret;
}
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index e5f1a56994c6..9f99af5b0b11 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -255,6 +255,7 @@ static void __j1939_session_drop(struct j1939_session *session)
return;
j1939_sock_pending_del(session->sk);
+ sock_put(session->sk);
}
static void j1939_session_destroy(struct j1939_session *session)
@@ -266,6 +267,9 @@ static void j1939_session_destroy(struct j1939_session *session)
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+ WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
+ WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
+
skb_queue_purge(&session->skb_queue);
__j1939_session_drop(session);
j1939_priv_put(session->priv);
@@ -1042,12 +1046,13 @@ j1939_session_deactivate_activate_next(struct j1939_session *session)
j1939_sk_queue_activate_next(session);
}
-static void j1939_session_cancel(struct j1939_session *session,
+static void __j1939_session_cancel(struct j1939_session *session,
enum j1939_xtp_abort err)
{
struct j1939_priv *priv = session->priv;
WARN_ON_ONCE(!err);
+ lockdep_assert_held(&session->priv->active_session_list_lock);
session->err = j1939_xtp_abort_to_errno(priv, err);
/* do not send aborts on incoming broadcasts */
@@ -1062,6 +1067,20 @@ static void j1939_session_cancel(struct j1939_session *session,
j1939_sk_send_loop_abort(session->sk, session->err);
}
+static void j1939_session_cancel(struct j1939_session *session,
+ enum j1939_xtp_abort err)
+{
+ j1939_session_list_lock(session->priv);
+
+ if (session->state >= J1939_SESSION_ACTIVE &&
+ session->state < J1939_SESSION_WAITING_ABORT) {
+ j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
+ __j1939_session_cancel(session, err);
+ }
+
+ j1939_session_list_unlock(session->priv);
+}
+
static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
{
struct j1939_session *session =
@@ -1108,8 +1127,6 @@ static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
__func__, session, ret);
if (session->skcb.addr.type != J1939_SIMPLE) {
- j1939_tp_set_rxtimeout(session,
- J1939_XTP_ABORT_TIMEOUT_MS);
j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
} else {
session->err = ret;
@@ -1169,7 +1186,7 @@ static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
hrtimer_start(&session->rxtimer,
ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
HRTIMER_MODE_REL_SOFT);
- j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
+ __j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
}
j1939_session_list_unlock(session->priv);
}
@@ -1375,7 +1392,6 @@ j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
out_session_cancel:
j1939_session_timers_cancel(session);
- j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
j1939_session_cancel(session, err);
}
@@ -1572,7 +1588,6 @@ static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
/* RTS on active session */
j1939_session_timers_cancel(session);
- j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
}
@@ -1583,7 +1598,6 @@ static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
session->last_cmd);
j1939_session_timers_cancel(session);
- j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
return -EBUSY;
@@ -1785,7 +1799,6 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,
out_session_cancel:
j1939_session_timers_cancel(session);
- j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
j1939_session_put(session);
}
@@ -1866,6 +1879,7 @@ struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
return ERR_PTR(-ENOMEM);
/* skb is recounted in j1939_session_new() */
+ sock_hold(skb->sk);
session->sk = skb->sk;
session->transmission = true;
session->pkt.total = (size + 6) / 7;
@@ -2028,7 +2042,11 @@ int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
&priv->active_session_list,
active_session_list_entry) {
if (!sk || sk == session->sk) {
- j1939_session_timers_cancel(session);
+ if (hrtimer_try_to_cancel(&session->txtimer) == 1)
+ j1939_session_put(session);
+ if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
+ j1939_session_put(session);
+
session->err = ESHUTDOWN;
j1939_session_deactivate_locked(session);
}