Hi Luiz,
> When receiving L2CAP_CREDIT_BASED_CONNECTION_REQ the remote may request
> more channels than allowed by the spec (10 octecs = 5 CIDs) so this
> truncates the response allowing it to create only the maximum allowed.
so what does the spec say the behavior should be? Truncate or actually respond with an error?
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> ---
> include/net/bluetooth/l2cap.h | 1 +
> net/bluetooth/l2cap_core.c | 4 ++--
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> index 61800a7b6192..3c4f550e5a8b 100644
> --- a/include/net/bluetooth/l2cap.h
> +++ b/include/net/bluetooth/l2cap.h
> @@ -494,6 +494,7 @@ struct l2cap_le_credits {
>
> #define L2CAP_ECRED_MIN_MTU 64
> #define L2CAP_ECRED_MIN_MPS 64
> +#define L2CAP_ECRED_MAX_CID 5
>
> struct l2cap_ecred_conn_req {
> __le16 psm;
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 72c2f5226d67..6325d4a89b31 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -5921,7 +5921,7 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
> struct l2cap_ecred_conn_req *req = (void *) data;
> struct {
> struct l2cap_ecred_conn_rsp rsp;
> - __le16 dcid[5];
> + __le16 dcid[L2CAP_ECRED_MAX_CID];
> } __packed pdu;
> struct l2cap_chan *chan, *pchan;
> u16 mtu, mps;
> @@ -5973,7 +5973,7 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
> cmd_len -= sizeof(*req);
> num_scid = cmd_len / sizeof(u16);
>
> - for (i = 0; i < num_scid; i++) {
> + for (i = 0; i < num_scid && i < ARRAY_SIZE(pdu.dcid); i++) {
> u16 scid = __le16_to_cpu(req->scid[i]);
>
> BT_DBG("scid[%d] 0x%4.4x", i, scid);
Is this really a good idea? I would prefer if we check the size first and then just respond with an error.
Regards
Marcel
