From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:37696 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750902AbdLSRek (ORCPT ); Tue, 19 Dec 2017 12:34:40 -0500 Date: Wed, 20 Dec 2017 02:34:39 +0900 From: Masakazu Mokuno To: Mathias Nyman Subject: Re: [PATCH] USB: Fix off by one in type-specific length check of BOS SSP capability Cc: , linux-usb@vger.kernel.org, linux-stable In-Reply-To: <1513674882-18422-1-git-send-email-mathias.nyman@linux.intel.com> References: <1513674882-18422-1-git-send-email-mathias.nyman@linux.intel.com> Message-Id: <20171220023435.9B5C.F48FD4B1@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: Hi Mathias, On Tue, 19 Dec 2017 11:14:42 +0200 Mathias Nyman wrote: > USB 3.1 devices are not detected as 3.1 capable since 4.15-rc3 due to a > off by one in commit 81cf4a45360f ("USB: core: Add type-specific length > check of BOS descriptors") > > It uses USB_DT_USB_SSP_CAP_SIZE() to get SSP capability size which takes > the zero based SSAC as argument, not the actual count of sublink speed > attributes. > > USB3 spec 9.6.2.5 says "The number of Sublink Speed Attributes = SSAC + 1." > > The type-specific length check patch was added to stable and needs to be > fixed there as well > > Fixes: 81cf4a45360f ("USB: core: Add type-specific length check of BOS descriptors") > Cc: linux-stable > CC: Masakazu Mokuno > Signed-off-by: Mathias Nyman > --- > drivers/usb/core/config.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c > index 78e92d2..c821b4b 100644 > --- a/drivers/usb/core/config.c > +++ b/drivers/usb/core/config.c > @@ -1007,7 +1007,7 @@ int usb_get_bos_descriptor(struct usb_device *dev) > case USB_SSP_CAP_TYPE: > ssp_cap = (struct usb_ssp_cap_descriptor *)buffer; > ssac = (le32_to_cpu(ssp_cap->bmAttributes) & > - USB_SSP_SUBLINK_SPEED_ATTRIBS) + 1; > + USB_SSP_SUBLINK_SPEED_ATTRIBS); > if (length >= USB_DT_USB_SSP_CAP_SIZE(ssac)) > dev->bos->ssp_cap = ssp_cap; > break; > -- > 2.7.4 Thanks for the fix. I got confused the meaning of USB_DT_USB_SSP_CAP_SIZE() just as you described. The sizeof(struct usb_ssp_cap_descriptor) is 16, but I did not noticed it included one SSAC. There's another place that wrongly uses USB_DT_USB_SSP_CAP_SIZE() in my previous patch. It should be fixed also. I'll make the patch. -- Masakazu Mokuno