scsi: cxlflash: Avoid double free of character device

BugLink: http://bugs.launchpad.net/bugs/1702521
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other issues as the reference is no longer valid after the first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>
(cherry picked from commit acfeb23b29894deaee65d63c55bea09183f6b538)
Signed-off-by: Victor Aoqui <victora@linux.vnet.ibm.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 7a787b6e21c4aaf4897db6fd205f9dce6faa119c..455564fb6c4db0d534df819b64617aaf35a52188 100644 (file)
--- 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);