From fbce985e28eaca3af82afecc11961aadaf971a7e Mon Sep 17 00:00:00 2001 From: Venkatesh Yadav Abbarapu Date: Thu, 3 Nov 2022 09:37:48 +0530 Subject: [PATCH] usb: gadget: dfu: Fix the unchecked length field DFU implementation does not bound the length field in USB DFU download setup packets, and it does not verify that the transfer direction. Fixing the length and transfer direction. CVE-2022-2347 Signed-off-by: Venkatesh Yadav Abbarapu Reviewed-by: Marek Vasut --- drivers/usb/gadget/f_dfu.c | 58 ++++++++++++++++++++++++-------------- 1 file changed, 37 insertions(+), 21 deletions(-) diff --git a/drivers/usb/gadget/f_dfu.c b/drivers/usb/gadget/f_dfu.c index e9340ff5cb..33ef62f8ba 100644 --- a/drivers/usb/gadget/f_dfu.c +++ b/drivers/usb/gadget/f_dfu.c @@ -321,23 +321,29 @@ static int state_dfu_idle(struct f_dfu *f_dfu, u16 len = le16_to_cpu(ctrl->wLength); int value = 0; + len = len > DFU_USB_BUFSIZ ? DFU_USB_BUFSIZ : len; + switch (ctrl->bRequest) { case USB_REQ_DFU_DNLOAD: - if (len == 0) { - f_dfu->dfu_state = DFU_STATE_dfuERROR; - value = RET_STALL; - break; + if (ctrl->bRequestType == USB_DIR_OUT) { + if (len == 0) { + f_dfu->dfu_state = DFU_STATE_dfuERROR; + value = RET_STALL; + break; + } + f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC; + f_dfu->blk_seq_num = w_value; + value = handle_dnload(gadget, len); } - f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC; - f_dfu->blk_seq_num = w_value; - value = handle_dnload(gadget, len); break; case USB_REQ_DFU_UPLOAD: - f_dfu->dfu_state = DFU_STATE_dfuUPLOAD_IDLE; - f_dfu->blk_seq_num = 0; - value = handle_upload(req, len); - if (value >= 0 && value < len) - f_dfu->dfu_state = DFU_STATE_dfuIDLE; + if (ctrl->bRequestType == USB_DIR_IN) { + f_dfu->dfu_state = DFU_STATE_dfuUPLOAD_IDLE; + f_dfu->blk_seq_num = 0; + value = handle_upload(req, len); + if (value >= 0 && value < len) + f_dfu->dfu_state = DFU_STATE_dfuIDLE; + } break; case USB_REQ_DFU_ABORT: /* no zlp? */ @@ -426,11 +432,15 @@ static int state_dfu_dnload_idle(struct f_dfu *f_dfu, u16 len = le16_to_cpu(ctrl->wLength); int value = 0; + len = len > DFU_USB_BUFSIZ ? DFU_USB_BUFSIZ : len; + switch (ctrl->bRequest) { case USB_REQ_DFU_DNLOAD: - f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC; - f_dfu->blk_seq_num = w_value; - value = handle_dnload(gadget, len); + if (ctrl->bRequestType == USB_DIR_OUT) { + f_dfu->dfu_state = DFU_STATE_dfuDNLOAD_SYNC; + f_dfu->blk_seq_num = w_value; + value = handle_dnload(gadget, len); + } break; case USB_REQ_DFU_ABORT: f_dfu->dfu_state = DFU_STATE_dfuIDLE; @@ -513,13 +523,17 @@ static int state_dfu_upload_idle(struct f_dfu *f_dfu, u16 len = le16_to_cpu(ctrl->wLength); int value = 0; + len = len > DFU_USB_BUFSIZ ? DFU_USB_BUFSIZ : len; + switch (ctrl->bRequest) { case USB_REQ_DFU_UPLOAD: - /* state transition if less data then requested */ - f_dfu->blk_seq_num = w_value; - value = handle_upload(req, len); - if (value >= 0 && value < len) - f_dfu->dfu_state = DFU_STATE_dfuIDLE; + if (ctrl->bRequestType == USB_DIR_IN) { + /* state transition if less data then requested */ + f_dfu->blk_seq_num = w_value; + value = handle_upload(req, len); + if (value >= 0 && value < len) + f_dfu->dfu_state = DFU_STATE_dfuIDLE; + } break; case USB_REQ_DFU_ABORT: f_dfu->dfu_state = DFU_STATE_dfuIDLE; @@ -595,6 +609,8 @@ dfu_handle(struct usb_function *f, const struct usb_ctrlrequest *ctrl) int value = 0; u8 req_type = ctrl->bRequestType & USB_TYPE_MASK; + len = len > DFU_USB_BUFSIZ ? DFU_USB_BUFSIZ : len; + debug("w_value: 0x%x len: 0x%x\n", w_value, len); debug("req_type: 0x%x ctrl->bRequest: 0x%x f_dfu->dfu_state: 0x%x\n", req_type, ctrl->bRequest, f_dfu->dfu_state); @@ -614,7 +630,7 @@ dfu_handle(struct usb_function *f, const struct usb_ctrlrequest *ctrl) value = dfu_state[f_dfu->dfu_state] (f_dfu, ctrl, gadget, req); if (value >= 0) { - req->length = value; + req->length = value > DFU_USB_BUFSIZ ? DFU_USB_BUFSIZ : value; req->zero = value < len; value = usb_ep_queue(gadget->ep0, req, 0); if (value < 0) { -- 2.39.5