Bluetooth: Errata Service Release 8, Erratum 3253

L2CAP: New result values
0x0006 - Connection refused – Invalid Source CID
0x0007 - Connection refused – Source CID already allocated

As per the ESR08_V1.0.0, 1.11.2 Erratum 3253, Page No. 54,
"Remote CID invalid Issue".
Applies to Core Specification versions: V5.0, V4.2, v4.1, v4.0, and v3.0 + HS
Vol 3, Part A, Section 4.2, 4.3, 4.14, 4.15.

Core Specification Version 5.0, Page No.1753, Table 4.6 and
Page No. 1767, Table 4.14

New result values are added to l2cap connect/create channel response as
0x0006 - Connection refused – Invalid Source CID
0x0007 - Connection refused – Source CID already allocated

Signed-off-by: Mallikarjun Phulari <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

include/net/bluetooth/l2cap.h

···
 #define L2CAP_CR_SEC_BLOCK	0x0003
 #define L2CAP_CR_NO_MEM		0x0004
 #define L2CAP_CR_BAD_AMP	0x0005
+#define L2CAP_CR_INVALID_SCID	0x0006
+#define L2CAP_CR_SCID_IN_USE	0x0007
 
 /* credit based connect results */
 #define L2CAP_CR_LE_SUCCESS		0x0000

net/bluetooth/l2cap_core.c

···
 
 	result = L2CAP_CR_NO_MEM;
 
-	/* Check if we already have channel with that dcid */
-	if (__l2cap_get_chan_by_dcid(conn, scid))
+	/* Check for valid dynamic CID range (as per Erratum 3253) */
+	if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
+		result = L2CAP_CR_INVALID_SCID;
 		goto response;
+	}
+
+	/* Check if we already have channel with that dcid */
+	if (__l2cap_get_chan_by_dcid(conn, scid)) {
+		result = L2CAP_CR_SCID_IN_USE;
+		goto response;
+	}
 
 	chan = pchan->ops->new_connection(pchan);
 	if (!chan)