+++ /dev/null
-From 3ae62a42090f1ed48e2313ed256a1182a85fb575 Mon Sep 17 00:00:00 2001
-From: Oliver Neukum <oneukum@suse.com>
-Date: Tue, 30 Apr 2019 12:21:45 +0200
-Subject: UAS: fix alignment of scatter/gather segments
-
-From: Oliver Neukum <oneukum@suse.com>
-
-commit 3ae62a42090f1ed48e2313ed256a1182a85fb575 upstream.
-
-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 <oneukum@suse.com>
-Cc: stable <stable@vger.kernel.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
----
- drivers/usb/storage/uas.c | 38 ++++++++++++++++++++++++--------------
- 1 file changed, 24 insertions(+), 14 deletions(-)
-
---- a/drivers/usb/storage/uas.c
-+++ b/drivers/usb/storage/uas.c
-@@ -783,23 +783,33 @@ static int uas_slave_alloc(struct scsi_d
- {
- 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.
-- *
-- * 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.
-+ /*
-+ * 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.
-+ *
-+ * 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));
-