From: Dan Carpenter Date: Mon, 11 Nov 2024 11:08:06 +0000 (+0300) Subject: usb: typec: fix potential array underflow in ucsi_ccg_sync_control() X-Git-Tag: v6.13-rc1~31^2~27 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e56aac6e5a25;p=linux-block.git 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: 170a6726d0e2 ("usb: typec: ucsi: add support for separate DP altmode devices") Signed-off-by: Dan Carpenter Reviewed-by: Heikki Krogerus Link: https://lore.kernel.org/r/c69ef0b3-61b0-4dde-98dd-97b97f81d912@stanley.mountain Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c index ba58d11907bc..ec813eb908a7 100644 --- a/drivers/usb/typec/ucsi/ucsi_ccg.c +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c @@ -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;