From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
According to the core specification the most recent value, not its
default, must be used in case it is missing on L2CAP_CONFIGURATION_REQ:
'Any missing configuration parameters are assumed to have their most
recently explicitly or implicitly accepted values.'
Fixes: c1360a1cf351 ("Bluetooth: use bit operation on conf_state")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 7b4adab353cf..7719f263f5c4 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3385,6 +3385,20 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
BT_DBG("chan %p", chan);
+ /* 4.4. L2CAP_CONFIGURATION_REQ (code 0x04):
+ * ...
+ * Any missing configuration parameters are assumed to have their most
+ * recently explicitly or implicitly accepted values.
+ */
+
+ /* If MTU has been previously set, use it instead of default. */
+ if (test_bit(CONF_MTU_DONE, &chan->conf_state))
+ mtu = chan->omtu;
+
+ /* If Mode has been previously set, use it instead of default. */
+ if (test_bit(CONF_MODE_DONE, &chan->conf_state))
+ rfc.mode = chan->mode;
+
while (len >= L2CAP_CONF_OPT_SIZE) {
len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
if (len < 0)
--
2.48.1
