+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;
+}
+