From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755828AbdEKP2A (ORCPT ); Thu, 11 May 2017 11:28:00 -0400 Received: from gateway21.websitewelcome.com ([192.185.45.250]:26558 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752770AbdEKP1l (ORCPT ); Thu, 11 May 2017 11:27:41 -0400 Date: Thu, 11 May 2017 10:27:35 -0500 From: "Gustavo A. R. Silva" To: Konrad Rzeszutek Wilk , Roger Pau =?iso-8859-1?Q?Monn=E9?= , Juergen Gross Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] block: xen-blkback: add null check to avoid null pointer dereference Message-ID: <20170511152735.GA4409@embeddedgus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170511100544.Horde.88c0RhMPEXYq42BauaUXfHV@gator4166.hostgator.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.152.186.83 X-Exim-ID: 1d8q08-0002IY-9n X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.152.186.83]:40706 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 10 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add null check before calling xen_blkif_put() to avoid potential null pointer dereference. Addresses-Coverity-ID: 1350942 Cc: Juergen Gross Signed-off-by: Gustavo A. R. Silva --- drivers/block/xen-blkback/xenbus.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 8fe61b5..1f3dfaa 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -504,11 +504,13 @@ static int xen_blkbk_remove(struct xenbus_device *dev) dev_set_drvdata(&dev->dev, NULL); - if (be->blkif) + if (be->blkif) { xen_blkif_disconnect(be->blkif); - /* Put the reference we set in xen_blkif_alloc(). */ - xen_blkif_put(be->blkif); + /* Put the reference we set in xen_blkif_alloc(). */ + xen_blkif_put(be->blkif); + } + kfree(be->mode); kfree(be); return 0; -- 2.5.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] block: xen-blkback: add null check to avoid null pointer dereference Date: Thu, 11 May 2017 10:27:35 -0500 Message-ID: <20170511152735.GA4409@embeddedgus> References: <20170511100544.Horde.88c0RhMPEXYq42BauaUXfHV@gator4166.hostgator.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d8q0D-00058r-AZ for xen-devel@lists.xenproject.org; Thu, 11 May 2017 15:27:41 +0000 Received: from cm1.websitewelcome.com (unknown [192.185.0.102]) by gateway31.websitewelcome.com (Postfix) with ESMTP id AFB37D778C for ; Thu, 11 May 2017 10:27:37 -0500 (CDT) Content-Disposition: inline In-Reply-To: <20170511100544.Horde.88c0RhMPEXYq42BauaUXfHV@gator4166.hostgator.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Konrad Rzeszutek Wilk , Roger Pau =?iso-8859-1?Q?Monn=E9?= , Juergen Gross Cc: xen-devel@lists.xenproject.org, "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org List-Id: xen-devel@lists.xenproject.org QWRkIG51bGwgY2hlY2sgYmVmb3JlIGNhbGxpbmcgeGVuX2Jsa2lmX3B1dCgpIHRvIGF2b2lkIHBv dGVudGlhbApudWxsIHBvaW50ZXIgZGVyZWZlcmVuY2UuCgpBZGRyZXNzZXMtQ292ZXJpdHktSUQ6 IDEzNTA5NDIKQ2M6IEp1ZXJnZW4gR3Jvc3MgPGpncm9zc0BzdXNlLmNvbT4KU2lnbmVkLW9mZi1i eTogR3VzdGF2byBBLiBSLiBTaWx2YSA8Z2Fyc2lsdmFAZW1iZWRkZWRvci5jb20+Ci0tLQogZHJp dmVycy9ibG9jay94ZW4tYmxrYmFjay94ZW5idXMuYyB8IDggKysrKystLS0KIDEgZmlsZSBjaGFu Z2VkLCA1IGluc2VydGlvbnMoKyksIDMgZGVsZXRpb25zKC0pCgpkaWZmIC0tZ2l0IGEvZHJpdmVy cy9ibG9jay94ZW4tYmxrYmFjay94ZW5idXMuYyBiL2RyaXZlcnMvYmxvY2sveGVuLWJsa2JhY2sv eGVuYnVzLmMKaW5kZXggOGZlNjFiNS4uMWYzZGZhYSAxMDA2NDQKLS0tIGEvZHJpdmVycy9ibG9j ay94ZW4tYmxrYmFjay94ZW5idXMuYworKysgYi9kcml2ZXJzL2Jsb2NrL3hlbi1ibGtiYWNrL3hl bmJ1cy5jCkBAIC01MDQsMTEgKzUwNCwxMyBAQCBzdGF0aWMgaW50IHhlbl9ibGtia19yZW1vdmUo c3RydWN0IHhlbmJ1c19kZXZpY2UgKmRldikKIAogCWRldl9zZXRfZHJ2ZGF0YSgmZGV2LT5kZXYs IE5VTEwpOwogCi0JaWYgKGJlLT5ibGtpZikKKwlpZiAoYmUtPmJsa2lmKSB7CiAJCXhlbl9ibGtp Zl9kaXNjb25uZWN0KGJlLT5ibGtpZik7CiAKLQkvKiBQdXQgdGhlIHJlZmVyZW5jZSB3ZSBzZXQg aW4geGVuX2Jsa2lmX2FsbG9jKCkuICovCi0JeGVuX2Jsa2lmX3B1dChiZS0+YmxraWYpOworCQkv KiBQdXQgdGhlIHJlZmVyZW5jZSB3ZSBzZXQgaW4geGVuX2Jsa2lmX2FsbG9jKCkuICovCisJCXhl bl9ibGtpZl9wdXQoYmUtPmJsa2lmKTsKKwl9CisKIAlrZnJlZShiZS0+bW9kZSk7CiAJa2ZyZWUo YmUpOwogCXJldHVybiAwOwotLSAKMi41LjAKCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fXwpYZW4tZGV2ZWwgbWFpbGluZyBsaXN0Clhlbi1kZXZlbEBsaXN0 cy54ZW4ub3JnCmh0dHBzOi8vbGlzdHMueGVuLm9yZy94ZW4tZGV2ZWwK