| Message ID | c69ef0b3-61b0-4dde-98dd-97b97f81d912@stanley.mountain |
|---|---|
| State | New |
| Headers | show |
| Series | usb: typec: fix potential array underflow in ucsi_ccg_sync_control() | expand |
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@linaro.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > 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
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;
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@linaro.org> --- drivers/usb/typec/ucsi/ucsi_ccg.c | 5 +++++ 1 file changed, 5 insertions(+)