Commit 4946096d authored by Johan Hedberg's avatar Johan Hedberg Committed by Marcel Holtmann

Bluetooth: Fix validating LE PSM values

LE PSM values have different ranges than those for BR/EDR. The valid
ranges for fixed, SIG assigned values is 0x0001-0x007f and for dynamic
PSM values 0x0080-0x00ff. We need to ensure that bind() and connect()
calls conform to these ranges when operating on LE CoC sockets.
Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent e77af755
......@@ -1861,6 +1861,18 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
return c1;
}
static bool is_valid_psm(u16 psm, u8 dst_type)
{
if (!psm)
return false;
if (bdaddr_type_is_le(dst_type))
return (psm < 0x00ff);
/* PSM must be odd and lsb of upper byte must be 0 */
return ((psm & 0x0101) == 0x0001);
}
int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
bdaddr_t *dst, u8 dst_type)
{
......@@ -1881,8 +1893,7 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
l2cap_chan_lock(chan);
/* PSM must be odd and lsb of upper byte must be 0 */
if ((__le16_to_cpu(psm) & 0x0101) != 0x0001 && !cid &&
if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
chan->chan_type != L2CAP_CHAN_RAW) {
err = -EINVAL;
goto done;
......
......@@ -53,6 +53,32 @@ bool l2cap_is_socket(struct socket *sock)
}
EXPORT_SYMBOL(l2cap_is_socket);
static int l2cap_validate_bredr_psm(u16 psm)
{
/* PSM must be odd and lsb of upper byte must be 0 */
if ((psm & 0x0101) != 0x0001)
return -EINVAL;
/* Restrict usage of well-known PSMs */
if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE))
return -EACCES;
return 0;
}
static int l2cap_validate_le_psm(u16 psm)
{
/* Valid LE_PSM ranges are defined only until 0x00ff */
if (psm > 0x00ff)
return -EINVAL;
/* Restrict fixed, SIG assigned PSM values to CAP_NET_BIND_SERVICE */
if (psm <= 0x007f && !capable(CAP_NET_BIND_SERVICE))
return -EACCES;
return 0;
}
static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
{
struct sock *sk = sock->sk;
......@@ -94,17 +120,13 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
if (la.l2_psm) {
__u16 psm = __le16_to_cpu(la.l2_psm);
/* PSM must be odd and lsb of upper byte must be 0 */
if ((psm & 0x0101) != 0x0001) {
err = -EINVAL;
goto done;
}
if (la.l2_bdaddr_type == BDADDR_BREDR)
err = l2cap_validate_bredr_psm(psm);
else
err = l2cap_validate_le_psm(psm);
/* Restrict usage of well-known PSMs */
if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE)) {
err = -EACCES;
if (err)
goto done;
}
}
if (la.l2_cid)
......
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