From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from aserp2120.oracle.com ([141.146.126.78]:54912 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751240AbeECMgz (ORCPT ); Thu, 3 May 2018 08:36:55 -0400 Date: Thu, 3 May 2018 15:36:30 +0300 From: Dan Carpenter To: niklas.soderlund+renesas@ragnatech.se Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: [bug report] media: rcar-vin: add group allocator functions Message-ID: <20180503123630.GA19539@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Hello Niklas Söderlund, The patch 3bb4c3bc85bf: "media: rcar-vin: add group allocator functions" from Apr 14, 2018, leads to the following static checker warning: drivers/media/platform/rcar-vin/rcar-core.c:346 rvin_group_put() error: potential NULL dereference 'vin->group'. drivers/media/platform/rcar-vin/rcar-core.c 339 static void rvin_group_put(struct rvin_dev *vin) 340 { 341 mutex_lock(&vin->group->lock); 342 343 vin->group = NULL; ^^^^^^^^^^^^^^^^^ Set to NULL. 344 vin->v4l2_dev.mdev = NULL; 345 346 if (WARN_ON(vin->group->vin[vin->id] != vin)) ^^^^^^^^^^^^^^^^^^^^^^^^ 347 goto out; 348 349 vin->group->vin[vin->id] = NULL; ^^^^^^^^^^^^^^^^^^^^^^^^ 350 out: 351 mutex_unlock(&vin->group->lock); ^^^^^^^^^^^^^^^^ 352 353 kref_put(&vin->group->refcount, rvin_group_release); ^^^^^^^^^^^^^^^^^^^^ There are a bunch of NULL dereferences here... 354 } regards, dan carpenter