From acfeb23b29894deaee65d63c55bea09183f6b538 Mon Sep 17 00:00:00 2001
From: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>
Date: Wed, 28 Jun 2017 12:14:21 -0500
Subject: [PATCH] scsi: cxlflash: Avoid double free of character device

References: fate#322239
Patch-mainline: v4.13-rc1
Git-commit: acfeb23b29894deaee65d63c55bea09183f6b538

The device_unregister() service used when cleaning up the character
device is already responsible for the internal state associated with the
device upon successful creation. As the cxlflash driver does not obtain
a second reference to the character device, the explicit call to
put_device() is not required and can lead to an inconsistent sysfs among
other issues as the reference is no longer valid after the first
put_device() is performed.

Remove the unnecessary put_device() to remedy this issue.

Fixes: a834a36b57d9 ("scsi: cxlflash: Create character device to provide host management interface")
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 drivers/scsi/cxlflash/main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 7a787b6e21c4..455564fb6c4d 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -923,7 +923,6 @@ static void cxlflash_put_minor(int minor)
  */
 static void cxlflash_release_chrdev(struct cxlflash_cfg *cfg)
 {
-	put_device(cfg->chardev);
 	device_unregister(cfg->chardev);
 	cfg->chardev = NULL;
 	cdev_del(&cfg->cdev);
-- 
2.10.2