According to Core Spec Version 5.2 | Vol 3, Part A 6.1.5, the incoming L2CAP_ConfigReq should be handled during OPEN state. The section below shows the btmon trace when running L2CAP/COS/CFD/BV-12-C before and after this change. === Before === ... > ACL Data RX: Handle 256 flags 0x02 dlen 12 #22 L2CAP: Connection Request (0x02) ident 2 len 4 PSM: 1 (0x0001) Source CID: 65 < ACL Data TX: Handle 256 flags 0x00 dlen 16 #23 L2CAP: Connection Response (0x03) ident 2 len 8 Destination CID: 64 Source CID: 65 Result: Connection successful (0x0000) Status: No further information available (0x0000) < ACL Data TX: Handle 256 flags 0x00 dlen 12 #24 L2CAP: Configure Request (0x04) ident 2 len 4 Destination CID: 65 Flags: 0x0000 > HCI Event: Number of Completed Packets (0x13) plen 5 #25 Num handles: 1 Handle: 256 Count: 1 > HCI Event: Number of Completed Packets (0x13) plen 5 #26 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 16 #27 L2CAP: Configure Request (0x04) ident 3 len 8 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 .. < ACL Data TX: Handle 256 flags 0x00 dlen 18 #28 L2CAP: Configure Response (0x05) ident 3 len 10 Source CID: 65 Flags: 0x0000 Result: Success (0x0000) Option: Maximum Transmission Unit (0x01) [mandatory] MTU: 672 > HCI Event: Number of Completed Packets (0x13) plen 5 #29 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 14 #30 L2CAP: Configure Response (0x05) ident 2 len 6 Source CID: 64 Flags: 0x0000 Result: Success (0x0000) > ACL Data RX: Handle 256 flags 0x02 dlen 20 #31 L2CAP: Configure Request (0x04) ident 3 len 12 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 91 02 11 11 ...... < ACL Data TX: Handle 256 flags 0x00 dlen 14 #32 L2CAP: Command Reject (0x01) ident 3 len 6 Reason: Invalid CID in request (0x0002) Destination CID: 64 Source CID: 65 > HCI Event: Number of Completed Packets (0x13) plen 5 #33 Num handles: 1 Handle: 256 Count: 1 ... === After === ... > ACL Data RX: Handle 256 flags 0x02 dlen 12 #22 L2CAP: Connection Request (0x02) ident 2 len 4 PSM: 1 (0x0001) Source CID: 65 < ACL Data TX: Handle 256 flags 0x00 dlen 16 #23 L2CAP: Connection Response (0x03) ident 2 len 8 Destination CID: 64 Source CID: 65 Result: Connection successful (0x0000) Status: No further information available (0x0000) < ACL Data TX: Handle 256 flags 0x00 dlen 12 #24 L2CAP: Configure Request (0x04) ident 2 len 4 Destination CID: 65 Flags: 0x0000 > HCI Event: Number of Completed Packets (0x13) plen 5 #25 Num handles: 1 Handle: 256 Count: 1 > HCI Event: Number of Completed Packets (0x13) plen 5 #26 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 16 #27 L2CAP: Configure Request (0x04) ident 3 len 8 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 .. < ACL Data TX: Handle 256 flags 0x00 dlen 18 #28 L2CAP: Configure Response (0x05) ident 3 len 10 Source CID: 65 Flags: 0x0000 Result: Success (0x0000) Option: Maximum Transmission Unit (0x01) [mandatory] MTU: 672 > HCI Event: Number of Completed Packets (0x13) plen 5 #29 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 14 #30 L2CAP: Configure Response (0x05) ident 2 len 6 Source CID: 64 Flags: 0x0000 Result: Success (0x0000) > ACL Data RX: Handle 256 flags 0x02 dlen 20 #31 L2CAP: Configure Request (0x04) ident 3 len 12 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 91 02 11 11 ..... < ACL Data TX: Handle 256 flags 0x00 dlen 18 #32 L2CAP: Configure Response (0x05) ident 3 len 10 Source CID: 65 Flags: 0x0000 Result: Success (0x0000) Option: Maximum Transmission Unit (0x01) [mandatory] MTU: 672 < ACL Data TX: Handle 256 flags 0x00 dlen 12 #33 L2CAP: Configure Request (0x04) ident 3 len 4 Destination CID: 65 Flags: 0x0000 > HCI Event: Number of Completed Packets (0x13) plen 5 #34 Num handles: 1 Handle: 256 Count: 1 > HCI Event: Number of Completed Packets (0x13) plen 5 #35 Num handles: 1 Handle: 256 Count: 1 ... Signed-off-by: Howard Chung <howardchung@xxxxxxxxxx> --- Changes in v2: - Updated commit messages net/bluetooth/l2cap_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 697c0f7f2c1a..5e6e35ab44dd 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4300,7 +4300,8 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, return 0; } - if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) { + if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 && + chan->state != BT_CONNECTED) { cmd_reject_invalid_cid(conn, cmd->ident, chan->scid, chan->dcid); goto unlock; -- 2.25.1.481.gfbce0eb801-goog