Commit e56aac6e authored by Dan Carpenter's avatar Dan Carpenter Committed by Greg Kroah-Hartman
Browse files

usb: typec: fix potential array underflow in ucsi_ccg_sync_control() 



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: 170a6726 ("usb: typec: ucsi: add support for separate DP altmode devices")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/c69ef0b3-61b0-4dde-98dd-97b97f81d912@stanley.mountain


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2481af79

drivers/usb/typec/ucsi/ucsi_ccg.c

+5 −0
Original line number Diff line number Diff line
@@ -642,6 +642,10 @@ 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);

	}
@@ -649,6 +653,7 @@ 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;