Bluetooth: Validate PSM values in calls to connect() and bind()
Valid L2CAP PSMs are odd numbers, and the least significant bit of the
most significant byte must be 0.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 0b54b7d..2f625b8 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1008,10 +1008,20 @@
goto done;
}
- if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
- !capable(CAP_NET_BIND_SERVICE)) {
- err = -EACCES;
- goto done;
+ 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;
+ }
+
+ /* Restrict usage of well-known PSMs */
+ if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE)) {
+ err = -EACCES;
+ goto done;
+ }
}
write_lock_bh(&l2cap_sk_list.lock);
@@ -1190,6 +1200,13 @@
goto done;
}
+ /* PSM must be odd and lsb of upper byte must be 0 */
+ if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001 &&
+ sk->sk_type != SOCK_RAW) {
+ err = -EINVAL;
+ goto done;
+ }
+
/* Set destination address and psm */
bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr);
l2cap_pi(sk)->psm = la.l2_psm;