Patch "scsi: sg: fix static checker warning in sg_is_valid_dxfer" 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 static checker warning in sg_is_valid_dxfer

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-static-checker-warning-in-sg_is_valid_dxfer.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: Mon, 17 Jul 2017 15:11:42 +0200
Subject: scsi: sg: fix static checker warning in sg_is_valid_dxfer

From: Johannes Thumshirn <[email protected]>

commit 14074aba4bcda3764c9a702b276308b89901d5b6 upstream.

dxfer_len is an unsigned int and we always assign a value > 0 to it, so it doesn't make any sense to check if it is < 0. We can't really check dxferp as well as we have both NULL and not NULL cases in the possible call paths.

So just return true for SG_DXFER_FROM_DEV transfer in sg_is_valid_dxfer().

---
 drivers/scsi/sg.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

@@ -770,8 +770,11 @@ static bool sg_is_valid_dxfer(sg_io_hdr_
 			return false;
 		return true;
 	case SG_DXFER_FROM_DEV:
-		if (hp->dxfer_len < 0)
-			return false;
+		/*
+		 * for SG_DXFER_FROM_DEV we always set dxfer_len to > 0. dxferp
+		 * can either be NULL or != NULL so there's no point in checking
+		 * it either. So just return true.
+		 */
 		return true;
 	case SG_DXFER_TO_DEV:
 	case SG_DXFER_TO_FROM_DEV:

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