cherryusb.git/core/usbh_core.c, branch master

fix(usbh): bounds-check cur_ep before writing ep[] in parse_config_descriptor (#426)

2026-07-17T01:43:01Z

* fix(usbh): check cur_ep against CONFIG_USBHOST_MAX_ENDPOINTS before writing ep[] parse_config_descriptor() checks cur_ep_num (the interface descriptor's self-declared bNumEndpoints) against CONFIG_USBHOST_MAX_ENDPOINTS when the INTERFACE descriptor is parsed, but cur_ep (the actual write index, incremented once per ENDPOINT sub-descriptor encountered in the byte stream) is never bounds-checked in the USB_DESCRIPTOR_TYPE_ENDPOINT case before the memcpy. A non-conformant or malicious device can declare a small bNumEndpoints while still emitting more ENDPOINT descriptors than declared in the raw config descriptor byte stream, causing cur_ep to exceed CONFIG_USBHOST_MAX_ENDPOINTS and the memcpy to write past the ep[] array, past altsetting[], and potentially past the whole usbh_configuration struct. Add the same bounds check pattern already used for cur_iface and cur_alt_setting two cases above, applied to cur_ep before the memcpy. * Allow interfaces to use configured capacity Endpoint counts are quantities, so a declaration equal to the endpoint array capacity is valid. The per-index guard still rejects descriptors that contain more endpoint records than the storage can hold. Constraint: Preserve the new cur_ep index guard Confidence: high Scope-risk: narrow Tested: Real parser matrix for declared/actual 3/3, 4/4, 5/5, and 3/5; MinGW and WSL GCC13 ASan+UBSan Not-tested: Physical USB device enumeration

fix(security): check desc len overflow

2026-07-14T02:54:43Z