From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:41987 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243AbdHXLEg (ORCPT ); Thu, 24 Aug 2017 07:04:36 -0400 Date: Thu, 24 Aug 2017 14:04:12 +0300 From: Dan Carpenter To: bart.vanassche@wdc.com Cc: linux-block@vger.kernel.org Subject: [bug report] skd: Avoid that module unloading triggers a use-after-free Message-ID: <20170824110412.uh27qkhutnrid7ji@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org Hello Bart Van Assche, This is a semi-automatic email about new static checker warnings. The patch 7277cc67b391: "skd: Avoid that module unloading triggers a use-after-free" from Aug 17, 2017, leads to the following Smatch complaint: drivers/block/skd_main.c:3080 skd_free_disk() error: we previously assumed 'disk' could be null (see line 3074) drivers/block/skd_main.c 3073 3074 if (disk && (disk->flags & GENHD_FL_UP)) ^^^^ Existing code checked for NULL. The new code shuffles things around. 3075 del_gendisk(disk); 3076 3077 if (skdev->queue) { 3078 blk_cleanup_queue(skdev->queue); 3079 skdev->queue = NULL; 3080 disk->queue = NULL; ^^^^^^^^^^^ Now we don't check here. 3081 } 3082 regards, dan carpenter