Bluetooth: Prevent uninitialized data access in L2CAP configuration
When configuring an ERTM or streaming mode connection, remote devices
are expected to send an RFC option in a successful config response. A
misbehaving remote device might not send an RFC option, and the L2CAP
code should not access uninitialized data in this case.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 5ea94a1..17b5b1c 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2152,7 +2152,7 @@
void *ptr = req->data;
int type, olen;
unsigned long val;
- struct l2cap_conf_rfc rfc;
+ struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
@@ -2271,6 +2271,16 @@
}
}
+ /* Use sane default values in case a misbehaving remote device
+ * did not send an RFC option.
+ */
+ rfc.mode = chan->mode;
+ rfc.retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
+ rfc.monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
+ rfc.max_pdu_size = cpu_to_le16(chan->imtu);
+
+ BT_ERR("Expected RFC option was not found, using defaults");
+
done:
switch (rfc.mode) {
case L2CAP_MODE_ERTM: