[PATCH 6.18 123/212] Bluetooth: LE L2CAP: Disconnect if sum of payload sizes exceed SDU

Greg Kroah-Hartman
2026-03-23T14:07:18Z

From: Christian Eggers <ceggers@arri.de>

[ Upstream commit b6a2bf43aa37670432843bc73ae2a6288ba4d6f8 ]

Core 6.0, Vol 3, Part A, 3.4.3:
"... If the sum of the payload sizes for the K-frames exceeds the
specified SDU length, the receiver shall disconnect the channel."

This fixes L2CAP/LE/CFC/BV-27-C (running together with 'l2test -r -P
0x0027 -V le_public').

Fixes: aac23bf63659 ("Bluetooth: Implement LE L2CAP reassembly")
Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/bluetooth/l2cap_core.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 1618fe98dce71..05acc2e98f58f 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -6721,6 +6721,7 @@ static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)

if (chan->sdu->len + skb->len > chan->sdu_len) {
BT_ERR("Too much LE L2CAP data received");
+ l2cap_send_disconn_req(chan, ECONNRESET);
err = -EINVAL;
goto failed;
}
--
2.51.0