Patch "scsi: sg: fix SG_DXFER_FROM_DEV transfers" has been added to the 3.18-stable tree

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 3.18-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-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Johannes Thumshirn <[email protected]>
Date: Fri, 7 Jul 2017 10:56:38 +0200
Subject: scsi: sg: fix SG_DXFER_FROM_DEV transfers

From: Johannes Thumshirn <[email protected]>

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")

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

@@ -769,8 +769,11 @@ 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 [email protected] are

queue-3.18/scsi-sg-fix-static-checker-warning-in-sg_is_valid_dxfer.patch queue-3.18/scsi-sg-only-check-for-dxfer_len-greater-than-256m.patch queue-3.18/scsi-sg-check-for-valid-direction-before-starting-the-request.patch queue-3.18/scsi-sg-close-race-condition-in-sg_remove_sfp_usercontext.patch queue-3.18/scsi-sg-fix-sg_dxfer_from_dev-transfers.patch