* [PATCH] usb: typec: fix potential array underflow in ucsi_ccg_sync_control()
@ 2024-11-11 11:08 Dan Carpenter
2024-11-12 11:51 ` Heikki Krogerus
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2024-11-11 11:08 UTC (permalink / raw)
To: Ajay Gupta
Cc: Heikki Krogerus, Greg Kroah-Hartman, Dmitry Baryshkov,
Uwe Kleine-König, Haotien Hsu, linux-usb, linux-kernel,
kernel-janitors
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(+)
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
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] usb: typec: fix potential array underflow in ucsi_ccg_sync_control()
2024-11-11 11:08 [PATCH] usb: typec: fix potential array underflow in ucsi_ccg_sync_control() Dan Carpenter
@ 2024-11-12 11:51 ` Heikki Krogerus
0 siblings, 0 replies; 2+ messages in thread
From: Heikki Krogerus @ 2024-11-12 11:51 UTC (permalink / raw)
To: Dan Carpenter
Cc: Ajay Gupta, Greg Kroah-Hartman, Dmitry Baryshkov,
Uwe Kleine-König, Haotien Hsu, linux-usb, linux-kernel,
kernel-janitors
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
--
heikki
^ permalink raw reply [flat|nested] 2+ messages in thread
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