Patch "scsi: sg: fix SG_DXFER_FROM_DEV transfers" has been added to the 4.12-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    scsi: sg: fix SG_DXFER_FROM_DEV transfers

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-sg-fix-sg_dxfer_from_dev-transfers.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 68c59fcea1f2c6a54c62aa896cc623c1b5bc9b47 Mon Sep 17 00:00:00 2001
From: Johannes Thumshirn <jthumshirn@suse.de>
Date: Fri, 7 Jul 2017 10:56:38 +0200
Subject: scsi: sg: fix SG_DXFER_FROM_DEV transfers

From: Johannes Thumshirn <jthumshirn@suse.de>

commit 68c59fcea1f2c6a54c62aa896cc623c1b5bc9b47 upstream.

SG_DXFER_FROM_DEV transfers do not necessarily have a dxferp as we set
it to NULL for the old sg_io read/write interface, but must have a
length bigger than 0. This fixes a regression introduced by commit
28676d869bbb ("scsi: sg: check for valid direction before starting the
request")

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 28676d869bbb ("scsi: sg: check for valid direction before starting the request")
Reported-by: Chris Clayton <chris2553@googlemail.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/sg.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -758,8 +758,11 @@ static bool sg_is_valid_dxfer(sg_io_hdr_
 		if (hp->dxferp || hp->dxfer_len > 0)
 			return false;
 		return true;
-	case SG_DXFER_TO_DEV:
 	case SG_DXFER_FROM_DEV:
+		if (hp->dxfer_len < 0)
+			return false;
+		return true;
+	case SG_DXFER_TO_DEV:
 	case SG_DXFER_TO_FROM_DEV:
 		if (!hp->dxferp || hp->dxfer_len == 0)
 			return false;


Patches currently in stable-queue which might be from jthumshirn@suse.de are

queue-4.12/scsi-sg-fix-sg_dxfer_from_dev-transfers.patch