CVE-2026-93118usb: gadget: aspeed_udc: check endpoint DMA allocation

Official description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: aspeed_udc: check endpoint DMA allocation 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/d7ae1a48e70e9c3451b7dc7bc3896c82884bc4df
• https://git.kernel.org/stable/c/4aaad88f857498ed1294f061f0b25d27ae891c55
• https://git.kernel.org/stable/c/6182e708e2e1f55521c8a01d7535630ecc2d7df9
• https://git.kernel.org/stable/c/ff6e88e29965bd06f640e59acdcf0bbf04a7f55c
• https://git.kernel.org/stable/c/9e6f57107c1886052d4baaa047a2bc3d0e91be5d
• https://git.kernel.org/stable/c/97cee53a94be3bd4fd8fbed6071bd2f32dad1ab1