This is a note to let you know that I've just added the patch titled
Bluetooth: L2CAP: Add missing checks for invalid DCID
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bluetooth-l2cap-add-missing-checks-for-invalid-dcid.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c54ff72f64728d4df4447ac0ccb3c6d7aeacbadb
Author: Sungwoo Kim <iam@xxxxxxxxxxxx>
Date: Sat Jun 3 08:28:09 2023 -0400
Bluetooth: L2CAP: Add missing checks for invalid DCID
[ Upstream commit 75767213f3d9b97f63694d02260b6a49a2271876 ]
When receiving a connect response we should make sure that the DCID is
within the valid range and that we don't already have another channel
allocated for the same DCID.
Missing checks may violate the specification (BLUETOOTH CORE SPECIFICATION
Version 5.4 | Vol 3, Part A, Page 1046).
Fixes: 40624183c202 ("Bluetooth: L2CAP: Add missing checks for invalid LE DCID")
Signed-off-by: Sungwoo Kim <iam@xxxxxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 6bbe0fd79d154..e56863587ea2e 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4024,6 +4024,10 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
result = __le16_to_cpu(rsp->result);
status = __le16_to_cpu(rsp->status);
+ if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START ||
+ dcid > L2CAP_CID_DYN_END))
+ return -EPROTO;
+
BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
dcid, scid, result, status);
@@ -4055,6 +4059,11 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
switch (result) {
case L2CAP_CR_SUCCESS:
+ if (__l2cap_get_chan_by_dcid(conn, dcid)) {
+ err = -EBADSLT;
+ break;
+ }
+
l2cap_state_change(chan, BT_CONFIG);
chan->ident = 0;
chan->dcid = dcid;
