From patchwork Thu Jul 21 11:32:04 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Savkov X-Patchwork-Id: 9241507 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 872BD602F0 for ; Thu, 21 Jul 2016 11:32:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5F77027C0B for ; Thu, 21 Jul 2016 11:32:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3F15327E22; Thu, 21 Jul 2016 11:32:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE0C327C0B for ; Thu, 21 Jul 2016 11:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751706AbcGULcn (ORCPT ); Thu, 21 Jul 2016 07:32:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47660 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751468AbcGULcm (ORCPT ); Thu, 21 Jul 2016 07:32:42 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C6AE9C05AA4C; Thu, 21 Jul 2016 11:32:41 +0000 (UTC) Received: from shodan.usersys.redhat.com (dhcp-1-150.brq.redhat.com [10.34.1.150]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u6LBWex8010777; Thu, 21 Jul 2016 07:32:41 -0400 Received: by shodan.usersys.redhat.com (Postfix, from userid 1000) id 3D1292C1A4F; Thu, 21 Jul 2016 13:32:40 +0200 (CEST) From: Artem Savkov To: Christoph Hellwig Cc: Anna Schumaker , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, trond.myklebust@primarydata.com, Artem Savkov Subject: [PATCH v3] Fix NULL pointer dereference in bl_free_device(). Date: Thu, 21 Jul 2016 13:32:04 +0200 Message-Id: <1469100724-11039-1-git-send-email-asavkov@redhat.com> In-Reply-To: <20160721080910.GA20363@lst.de> References: <20160721080910.GA20363@lst.de> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 21 Jul 2016 11:32:41 +0000 (UTC) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When bl_parse_deviceid() fails in bl_alloc_deviceid_node() on blkdev_get_by_*() step we get an pnfs_block_dev struct that is uninitialized except for bdev field which is set to whatever error blkdev_get_by_*() returns. bl_free_device() then tries to call blkdev_put() if bdev is not 0 resulting in a wrong pointer dereference. Fixing this by setting bdev in struct pnfs_block_dev only if we didn't get an error from blkdev_get_by_*(). Signed-off-by: Artem Savkov Reviewed-by: Benjamin Coddington --- fs/nfs/blocklayout/dev.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c index 118252f..a69ef4e 100644 --- a/fs/nfs/blocklayout/dev.c +++ b/fs/nfs/blocklayout/dev.c @@ -235,18 +235,20 @@ bl_parse_simple(struct nfs_server *server, struct pnfs_block_dev *d, struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask) { struct pnfs_block_volume *v = &volumes[idx]; + struct block_device *bdev; dev_t dev; dev = bl_resolve_deviceid(server, v, gfp_mask); if (!dev) return -EIO; - d->bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL); - if (IS_ERR(d->bdev)) { + bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL); + if (IS_ERR(bdev)) { printk(KERN_WARNING "pNFS: failed to open device %d:%d (%ld)\n", - MAJOR(dev), MINOR(dev), PTR_ERR(d->bdev)); - return PTR_ERR(d->bdev); + MAJOR(dev), MINOR(dev), PTR_ERR(bdev)); + return PTR_ERR(bdev); } + d->bdev = bdev; d->len = i_size_read(d->bdev->bd_inode); @@ -350,17 +352,19 @@ bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d, struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask) { struct pnfs_block_volume *v = &volumes[idx]; + struct block_device *bdev; const struct pr_ops *ops; int error; if (!bl_validate_designator(v)) return -EINVAL; - d->bdev = bl_open_dm_mpath_udev_path(v); - if (IS_ERR(d->bdev)) - d->bdev = bl_open_udev_path(v); - if (IS_ERR(d->bdev)) - return PTR_ERR(d->bdev); + bdev = bl_open_dm_mpath_udev_path(v); + if (IS_ERR(bdev)) + bdev = bl_open_udev_path(v); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + d->bdev = bdev; d->len = i_size_read(d->bdev->bd_inode); d->map = bl_map_simple;