Hi Luiz,
On Mon, 2022-10-31 at 16:10 -0700, Luiz Augusto von Dentz wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
>
> The Bluetooth spec states that the valid range for SPSM is from
> 0x0001-0x00ff so it is invalid to accept values outside of this range:
>
> BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
> page 1059:
> Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
>
> CVE: CVE-2022-42896
> CC: stable@xxxxxxxxxxxxxxx
> Reported-by: Tamás Koczka <poprdi@xxxxxxxxxx>
Reviewed-by: Tedd Ho-Jeong An <tedd.an@xxxxxxxxx>
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> ---
> net/bluetooth/l2cap_core.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index ef725ed41303..2978a34ea33f 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -5813,6 +5813,19 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn,
> BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
> scid, mtu, mps);
>
> + /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
> + * page 1059:
> + *
> + * Valid range: 0x0001-0x00ff
> + *
> + * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
> + */
> + if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
> + result = L2CAP_CR_LE_BAD_PSM;
> + chan = NULL;
> + goto response;
> + }
> +
> /* Check if we have socket listening on psm */
> pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
> &conn->hcon->dst, LE_LINK);
> @@ -6001,6 +6014,18 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
>
> psm = req->psm;
>
> + /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
> + * page 1059:
> + *
> + * Valid range: 0x0001-0x00ff
> + *
> + * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
> + */
> + if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
> + result = L2CAP_CR_LE_BAD_PSM;
> + goto response;
> + }
> +
> BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
>
> memset(&pdu, 0, sizeof(pdu));
Regards,
Tedd
