On Mon, Nov 11, 2024 at 02:08:06PM +0300, Dan Carpenter wrote:
> The "command" variable can be controlled by the user via debugfs. The
> worry is that if con_index is zero then "&uc->ucsi->connector[con_index
> - 1]" would be an array underflow.
>
> Fixes: 170a6726d0e2 ("usb: typec: ucsi: add support for separate DP altmode devices")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/ucsi/ucsi_ccg.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
> index bccfc03b5986..fcb8e61136cf 100644
> --- a/drivers/usb/typec/ucsi/ucsi_ccg.c
> +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
> @@ -644,6 +644,10 @@ static int ucsi_ccg_sync_control(struct ucsi *ucsi, u64 command)
> uc->has_multiple_dp) {
> con_index = (uc->last_cmd_sent >> 16) &
> UCSI_CMD_CONNECTOR_MASK;
> + if (con_index == 0) {
> + ret = -EINVAL;
> + goto unlock;
> + }
> con = &uc->ucsi->connector[con_index - 1];
> ucsi_ccg_update_set_new_cam_cmd(uc, con, &command);
> }
> @@ -651,6 +655,7 @@ static int ucsi_ccg_sync_control(struct ucsi *ucsi, u64 command)
> ret = ucsi_sync_control_common(ucsi, command);
>
> pm_runtime_put_sync(uc->dev);
> +unlock:
> mutex_unlock(&uc->lock);
>
> return ret;
> --
> 2.45.2
--
heikki
