usb: cdns3: gadget: Use-after-free during failed initialization and exit of cdnsp...

In the __cdnsp_gadget_init() and cdnsp_gadget_exit() functions, the gadget
structure (pdev->gadget) was freed before its endpoints.
The endpoints are linked via the ep_list in the gadget structure.
Freeing the gadget first leaves dangling pointers in the endpoint list.
When the endpoints are subsequently freed, this results in a use-after-free.

Fix:
By separating the usb_del_gadget_udc() operation into distinct "del" and
"put" steps, cdnsp_gadget_free_endpoints() can be executed prior to the
final release of the gadget structure with usb_put_gadget().

A patch similar to bb9c74a5bd14("usb: dwc3: gadget: Free gadget structure
 only after freeing endpoints").

Signed-off-by: Chen Yufeng <chenyufeng@iie.ac.cn>
Link: https://lore.kernel.org/r/20250905094842.1232-1-chenyufeng@iie.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c
index 55f95f41b3b4dd880c0aea0d1ab9eaeca2e93a45..0252560cbc80bd80f81128f834ca4fe011d2fda8 100644 (file)
--- a/drivers/usb/cdns3/cdnsp-gadget.c
+++ b/drivers/usb/cdns3/cdnsp-gadget.c
@@ -1976,7 +1976,10 @@ static int __cdnsp_gadget_init(struct cdns *cdns)
        return 0;
 
 del_gadget:
-       usb_del_gadget_udc(&pdev->gadget);
+       usb_del_gadget(&pdev->gadget);
+       cdnsp_gadget_free_endpoints(pdev);
+       usb_put_gadget(&pdev->gadget);
+       goto halt_pdev;
 free_endpoints:
        cdnsp_gadget_free_endpoints(pdev);
 halt_pdev:
@@ -1998,8 +2001,9 @@ static void cdnsp_gadget_exit(struct cdns *cdns)
        devm_free_irq(pdev->dev, cdns->dev_irq, pdev);
        pm_runtime_mark_last_busy(cdns->dev);
        pm_runtime_put_autosuspend(cdns->dev);
-       usb_del_gadget_udc(&pdev->gadget);
+       usb_del_gadget(&pdev->gadget);
        cdnsp_gadget_free_endpoints(pdev);
+       usb_put_gadget(&pdev->gadget);
        cdnsp_mem_cleanup(pdev);
        kfree(pdev);
        cdns->gadget_dev = NULL;