[PATCH AUTOSEL 4.4 32/64] Bluetooth: L2CAP: handle l2cap config request during open state

From: Sasha Levin
Date: Thu Sep 17 2020 - 22:21:39 EST

From: Howard Chung <howardchung@xxxxxxxxxx>

[ Upstream commit 96298f640104e4cd9a913a6e50b0b981829b94ff ]

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>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 f6112f495a36c..f2db50da8ce2e 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4096,7 +4096,8 @@ 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