[ Upstream commit b25120e1d5 ]
L2CAP_ECRED_CONN_RSP needs to respond DCID in the same order received as
SCID but the order is reversed due to use of list_add which actually
prepend channels to the list so the response is reversed:
> ACL Data RX: Handle 16 flags 0x02 dlen 26
LE L2CAP: Enhanced Credit Connection Request (0x17) ident 2 len 18
PSM: 39 (0x0027)
MTU: 256
MPS: 251
Credits: 65535
Source CID: 116
Source CID: 117
Source CID: 118
Source CID: 119
Source CID: 120
< ACL Data TX: Handle 16 flags 0x00 dlen 26
LE L2CAP: Enhanced Credit Connection Response (0x18) ident 2 len 18
MTU: 517
MPS: 247
Credits: 3
Result: Connection successful (0x0000)
Destination CID: 68
Destination CID: 67
Destination CID: 66
Destination CID: 65
Destination CID: 64
Also make sure the response don't include channels that are not on
BT_CONNECT2 since the chan->ident can be set to the same value as in the
following trace:
< ACL Data TX: Handle 16 flags 0x00 dlen 12
LE L2CAP: LE Flow Control Credit (0x16) ident 6 len 4
Source CID: 64
Credits: 1
...
> ACL Data RX: Handle 16 flags 0x02 dlen 18
LE L2CAP: Enhanced Credit Connection Request (0x17) ident 6 len 10
PSM: 39 (0x0027)
MTU: 517
MPS: 251
Credits: 255
Source CID: 70
< ACL Data TX: Handle 16 flags 0x00 dlen 20
LE L2CAP: Enhanced Credit Connection Response (0x18) ident 6 len 12
MTU: 517
MPS: 247
Credits: 3
Result: Connection successful (0x0000)
Destination CID: 64
Destination CID: 68
Closes: https://github.com/bluez/bluez/issues/1094
Fixes: 9aa9d9473f ("Bluetooth: L2CAP: Fix responding with wrong PDU type")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Luiz Augusto von Dentz
fbe5582ad7