Patch "scsi: sg: fix static checker warning in sg_is_valid_dxfer" has been added to the 4.9-stable tree

Patch "scsi: sg: fix static checker warning in sg_is_valid_dxfer" has been added to the 4.9-stable tree

[gregkh]

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 4.9-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-4.9 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 14074aba4bcda3764c9a702b276308b89901d5b6 Mon Sep 17 00:00:00 2001
From: Johannes Thumshirn <jthumshirn@suse.de>
Date: Mon, 17 Jul 2017 15:11:42 +0200
Subject: scsi: sg: fix static checker warning in sg_is_valid_dxfer

From: Johannes Thumshirn <jthumshirn@suse.de>

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().

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reported-by: Colin Ian King <colin.king@canonical.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: 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 |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -759,8 +759,11 @@ 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 jthumshirn@suse.de are

queue-4.9/scsi-sg-fix-static-checker-warning-in-sg_is_valid_dxfer.patch
queue-4.9/scsi-sg-only-check-for-dxfer_len-greater-than-256m.patch
queue-4.9/scsi-sg-check-for-valid-direction-before-starting-the-request.patch
queue-4.9/scsi-sg-close-race-condition-in-sg_remove_sfp_usercontext.patch
queue-4.9/scsi-sg-fix-sg_dxfer_from_dev-transfers.patch
queue-4.9/scsi-core-scsi_get_device_flags_keyed-always-return-device-flags.patch