From b70dc75e85ba968b7b76eebfe5d63000080b875b Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Tue, 30 Jun 2026 00:50:04 +0500 Subject: [PATCH] usb: gadget: uvc: clamp SEND_RESPONSE length to the response buffer uvc_send_response() builds the UVC control response from a user-supplied struct uvc_request_data: req->length = min_t(unsigned int, uvc->event_length, data->length); ... memcpy(req->buf, data->data, req->length); req->length is clamped to uvc->event_length, which is taken from the host control request wLength (up to UVC_MAX_REQUEST_SIZE, 64), and to data->length, which comes from the UVCIOC_SEND_RESPONSE ioctl and is only checked for being negative. The source buffer data->data is only 60 bytes, so a response with uvc->event_length and data->length both greater than 60 makes memcpy() read past the end of data->data. Clamp req->length to sizeof(data->data) as well. Fixes: a5eaaa1f33e7 ("usb: gadget: uvc: use capped length value") Cc: stable Signed-off-by: Muhammad Bilal Link: https://patch.msgid.link/20260629195004.148405-1-meatuni001@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/uvc_v4l2.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c index 514e5930b9ca..dfa0521a243a 100644 --- a/drivers/usb/gadget/function/uvc_v4l2.c +++ b/drivers/usb/gadget/function/uvc_v4l2.c @@ -200,6 +200,8 @@ uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data) return usb_ep_set_halt(cdev->gadget->ep0); req->length = min_t(unsigned int, uvc->event_length, data->length); + if (req->length > sizeof(data->data)) + req->length = sizeof(data->data); req->zero = data->length < uvc->event_length; memcpy(req->buf, data->data, req->length);