Commit 87c5ff56 authored by Chen Yufeng's avatar Chen Yufeng Committed by Greg Kroah-Hartman
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usb: cdns3: gadget: Use-after-free during failed initialization and exit of cdnsp gadget 



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 bb9c74a5("usb: dwc3: gadget: Free gadget structure
 only after freeing endpoints").

Signed-off-by: default avatarChen Yufeng <chenyufeng@iie.ac.cn>
Link: https://lore.kernel.org/r/20250905094842.1232-1-chenyufeng@iie.ac.cn


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e9c20632

drivers/usb/cdns3/cdnsp-gadget.c

+6 −2
Original line number Diff line number Diff line
@@ -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;