Re: [PATCH v2] usb: gadget: aspeed_udc: check endpoint DMA allocation

[Andrew Jeffery <andrew@codeconstruct.com.au>]

On Wed, 2026-06-10 at 20:10 +0800, Ruoyu Wang wrote:
> ast_udc_probe() allocates a coherent DMA buffer used as the backing store
> for endpoint buffers. ast_udc_init_ep() derives per-endpoint buffer
> pointers from udc->ep0_buf, so a failed allocation is dereferenced during
> probe.
> 
> Check the allocation before endpoint setup. The existing probe error path
> called ast_udc_remove(), which unregisters the gadget unconditionally and
> is not safe before usb_add_gadget_udc() succeeds. Add a local cleanup
> helper for probe failures so pre-registration failures only unwind the
> resources that were actually initialized.
> 
> This was found by a local static analysis checker for unchecked allocator
> returns while scanning Linux 6.16. The change was checked by applying it
> to current mainline and by running checkpatch. I do not have access to
> Aspeed UDC hardware, so no runtime testing was performed.
> 
> Fixes: 055276c13205 ("usb: gadget: add Aspeed ast2600 udc driver")
> Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>

Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>