[PATCH AUTOSEL 5.10 43/44] Bluetooth: L2CAP: Fix possible multiple reject send

[Sasha Levin]

From: Frédéric Danis <frederic.danis@xxxxxxxxxxxxx>

[ Upstream commit 96a3398b467ab8aada3df2f3a79f4b7835d068b8 ]

In case of an incomplete command or a command with a null identifier 2
reject packets will be sent, one with the identifier and one with 0.
Consuming the data of the command will prevent it.
This allows to send a reject packet for each corrupted command in a
multi-command packet.

Signed-off-by: Frédéric Danis <frederic.danis@xxxxxxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/bluetooth/l2cap_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index cf78a48085ed..a752032e12fc 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -6522,7 +6522,8 @@ static inline void l2cap_sig_channel(struct l2cap_conn *conn,
 		if (len > skb->len || !cmd->ident) {
 			BT_DBG("corrupted command");
 			l2cap_sig_send_rej(conn, cmd->ident);
-			break;
+			skb_pull(skb, len > skb->len ? skb->len : len);
+			continue;
 		}
 
 		err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data);
-- 
2.43.0