Re: [PATCH v2] usb: gadget: udc-xilinx: guard EP0 dequeue against empty queue

[sashiko-bot@kernel.org]

> From: Wang Haoran <haoranwangsec@gmail.com>
> 
> The EP0 dequeue side, xudc_ep0_out() and xudc_ep0_in(), calls
> list_first_entry() on ep0->queue without checking whether a request is
> queued, while the enqueue side __xudc_ep0_queue() already guards the
> same queue with list_empty() and the non-control endpoint handler
> performs the same check before its own list_first_entry().
> 
> list_first_entry() never returns NULL on an empty list; it returns the
> container_of() of the list head, i.e. a non-NULL wild pointer into the
> enclosing struct xusb_ep. Switch both functions to
> list_first_entry_or_null() and return early when no request is queued,
> making the dequeue side consistent with the rest of the driver.
> 
> This is a defensive consistency fix found by static analysis.
> 
> Fixes: 1f7c51660034 ("usb: gadget: Add xilinx usb2 device support")
> Reported-by: Wang Haoran <haoranwangsec@gmail.com>
> Reported-by: Li Ximo <lixicaicai@gmail.com>
> Reviewed-by: Aldo Ariel Panzardo <qwe.aldo@gmail.com>
> Signed-off-by: Wang Haoran <haoranwangsec@gmail.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261103084722.1821982-1-lixicaicai@gmail.com?part=1