2022-07-18 16:12:54

by Andrey Strachuk

Subject: [PATCH v2] usb: cdns3: change place of 'priv_ep' assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable()

If 'ep' is NULL, result of ep_to_cdns3_ep(ep) is invalid pointer
and its dereference with priv_ep->cdns3_dev may cause panic.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Strachuk <[email protected]>
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
---
drivers/usb/cdns3/cdns3-gadget.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 5c15c48952a6..aea5db0ec72d 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2285,13 +2285,14 @@ static int cdns3_gadget_ep_enable(struct usb_ep *ep,
int val;

priv_ep = ep_to_cdns3_ep(ep);
- priv_dev = priv_ep->cdns3_dev;
- comp_desc = priv_ep->endpoint.comp_desc;

if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
return -EINVAL;
}
+
+ comp_desc = priv_ep->endpoint.comp_desc;
+ priv_dev = priv_ep->cdns3_dev;

if (!desc->wMaxPacketSize) {
dev_err(priv_dev->dev, "usbss: missing wMaxPacketSize\n");
@@ -2600,7 +2601,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
struct usb_request *request)
{
struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
- struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
+ struct cdns3_device *priv_dev;
struct usb_request *req, *req_temp;
struct cdns3_request *priv_req;
struct cdns3_trb *link_trb;
@@ -2610,6 +2611,8 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,

if (!ep || !request || !ep->desc)
return -EINVAL;
+
+ priv_dev = priv_ep->cdns3_dev;

spin_lock_irqsave(&priv_dev->lock, flags);

--
2.25.1

2022-07-27 09:24:32

by Peter Chen

Subject: Re: [PATCH v2] usb: cdns3: change place of 'priv_ep' assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable()

On 22-07-18 19:00:52, Andrey Strachuk wrote:
> If 'ep' is NULL, result of ep_to_cdns3_ep(ep) is invalid pointer
> and its dereference with priv_ep->cdns3_dev may cause panic.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Andrey Strachuk <[email protected]>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> ---
> drivers/usb/cdns3/cdns3-gadget.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index 5c15c48952a6..aea5db0ec72d 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -2285,13 +2285,14 @@ static int cdns3_gadget_ep_enable(struct usb_ep *ep,
> int val;
>
> priv_ep = ep_to_cdns3_ep(ep);
> - priv_dev = priv_ep->cdns3_dev;
> - comp_desc = priv_ep->endpoint.comp_desc;
>
> if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
> dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
> return -EINVAL;
> }
> +
> + comp_desc = priv_ep->endpoint.comp_desc;
> + priv_dev = priv_ep->cdns3_dev;
>
> if (!desc->wMaxPacketSize) {
> dev_err(priv_dev->dev, "usbss: missing wMaxPacketSize\n");
> @@ -2600,7 +2601,7 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
> struct usb_request *request)
> {
> struct cdns3_endpoint *priv_ep = ep_to_cdns3_ep(ep);
> - struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
> + struct cdns3_device *priv_dev;
> struct usb_request *req, *req_temp;
> struct cdns3_request *priv_req;
> struct cdns3_trb *link_trb;
> @@ -2610,6 +2611,8 @@ int cdns3_gadget_ep_dequeue(struct usb_ep *ep,
>
> if (!ep || !request || !ep->desc)
> return -EINVAL;
> +
> + priv_dev = priv_ep->cdns3_dev;
>
> spin_lock_irqsave(&priv_dev->lock, flags);
>
> --

Acked-by: Peter Chen <[email protected]>

--

Thanks,
Peter Chen