Bluetooth: L2CAP: Fix calling sk_filter on non-socket based channel

Only sockets will have the chan->data set to an actual sk, channels
like A2MP would have its own data which would likely cause a crash when
calling sk_filter, in order to fix this a new callback has been
introduced so channels can implement their own filtering if necessary.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Luiz Augusto von Dentz 2020-08-06 11:17:12 -07:00 committed by Marcel Holtmann
parent eddb773211
commit f19425641c
3 changed files with 20 additions and 3 deletions

View File

@ -665,6 +665,8 @@ struct l2cap_ops {
struct sk_buff *(*alloc_skb) (struct l2cap_chan *chan,
unsigned long hdr_len,
unsigned long len, int nb);
int (*filter) (struct l2cap_chan * chan,
struct sk_buff *skb);
};
struct l2cap_conn {

View File

@ -7301,9 +7301,10 @@ static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
goto drop;
}
if ((chan->mode == L2CAP_MODE_ERTM ||
chan->mode == L2CAP_MODE_STREAMING) && sk_filter(chan->data, skb))
goto drop;
if (chan->ops->filter) {
if (chan->ops->filter(chan, skb))
goto drop;
}
if (!control->sframe) {
int err;

View File

@ -1664,6 +1664,19 @@ static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
sk->sk_state_change(sk);
}
static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb)
{
struct sock *sk = chan->data;
switch (chan->mode) {
case L2CAP_MODE_ERTM:
case L2CAP_MODE_STREAMING:
return sk_filter(sk, skb);
}
return 0;
}
static const struct l2cap_ops l2cap_chan_ops = {
.name = "L2CAP Socket Interface",
.new_connection = l2cap_sock_new_connection_cb,
@ -1679,6 +1692,7 @@ static const struct l2cap_ops l2cap_chan_ops = {
.get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
.get_peer_pid = l2cap_sock_get_peer_pid_cb,
.alloc_skb = l2cap_sock_alloc_skb_cb,
.filter = l2cap_sock_filter,
};
static void l2cap_sock_destruct(struct sock *sk)