From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78D2BC43219 for ; Tue, 30 Apr 2019 15:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C3292173E for ; Tue, 30 Apr 2019 15:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556639519; bh=WVZFUYohFiYvreAxf5Tt015tsmqtRmgkCvidNoDR8k0=; h=Subject:To:From:Date:List-ID:From; b=Ckmc5C7pKMB1oTveWFujawXDydlgOPQHIN/B/iEpaVzYQN00LeqvxEgd++gAMbFJR bI/IIUnEUu3Ry11fAuv/FLaMk5HlFVtS4GQifgciCPlOj6Vfj+k116xqMng8epKLRi DQLVBULtM3RHCV59/KSAihCYv1J3iSZDpeAR3TdU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725906AbfD3Pv6 (ORCPT ); Tue, 30 Apr 2019 11:51:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:59878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725930AbfD3Pv6 (ORCPT ); Tue, 30 Apr 2019 11:51:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8F07D21734; Tue, 30 Apr 2019 15:51:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556639517; bh=WVZFUYohFiYvreAxf5Tt015tsmqtRmgkCvidNoDR8k0=; h=Subject:To:From:Date:From; b=VVhUqjPXhgdytyDlgIXd35I8JFOquw1JJZ3vYUoB+y9KJ0ic5z7sBp+EQ5QEkXmaF eOnI5gFR5zKLrE015KDQb8HEHCdnMbtz5J/jUES9wlDVCXKNIBORFV8WkqLPpWAW2T RlvPIIn0J3KYCG/Y2xf0Sf7BienQb1g4oYHifNE0= Subject: patch "UAS: fix alignment of scatter/gather segments" added to usb-testing To: oneukum@suse.com, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Tue, 30 Apr 2019 17:51:54 +0200 Message-ID: <155663951455105@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled UAS: fix alignment of scatter/gather segments to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the usb-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >From 3ae62a42090f1ed48e2313ed256a1182a85fb575 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Tue, 30 Apr 2019 12:21:45 +0200 Subject: UAS: fix alignment of scatter/gather segments This is the UAS version of 747668dbc061b3e62bc1982767a3a1f9815fcf0e usb-storage: Set virt_boundary_mask to avoid SG overflows We are not as likely to be vulnerable as storage, as it is unlikelier that UAS is run over a controller without native support for SG, but the issue exists. The issue has been existing since the inception of the driver. Fixes: 115bb1ffa54c ("USB: Add UAS driver") Signed-off-by: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/uas.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index a6d68191c861..047c5922618f 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -789,24 +789,33 @@ static int uas_slave_alloc(struct scsi_device *sdev) { struct uas_dev_info *devinfo = (struct uas_dev_info *)sdev->host->hostdata; + int maxp; sdev->hostdata = devinfo; /* - * USB has unusual DMA-alignment requirements: Although the - * starting address of each scatter-gather element doesn't matter, - * the length of each element except the last must be divisible - * by the Bulk maxpacket value. There's currently no way to - * express this by block-layer constraints, so we'll cop out - * and simply require addresses to be aligned at 512-byte - * boundaries. This is okay since most block I/O involves - * hardware sectors that are multiples of 512 bytes in length, - * and since host controllers up through USB 2.0 have maxpacket - * values no larger than 512. + * We have two requirements here. We must satisfy the requirements + * of the physical HC and the demands of the protocol, as we + * definitely want no additional memory allocation in this path + * ruling out using bounce buffers. * - * But it doesn't suffice for Wireless USB, where Bulk maxpacket - * values can be as large as 2048. To make that work properly - * will require changes to the block layer. + * For a transmission on USB to continue we must never send + * a package that is smaller than maxpacket. Hence the length of each + * scatterlist element except the last must be divisible by the + * Bulk maxpacket value. + * If the HC does not ensure that through SG, + * the upper layer must do that. We must assume nothing + * about the capabilities off the HC, so we use the most + * pessimistic requirement. + */ + + maxp = usb_maxpacket(devinfo->udev, devinfo->data_in_pipe, 0); + blk_queue_virt_boundary(sdev->request_queue, maxp - 1); + + /* + * The protocol has no requirements on alignment in the strict sense. + * Controllers may or may not have alignment restrictions. + * As this is not exported, we use an extremely conservative guess. */ blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1)); -- 2.21.0