From patchwork Fri Mar 17 18:48:15 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 740452 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vlDwb3JKKz9ryr for ; Sat, 18 Mar 2017 05:52:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751761AbdCQSvJ (ORCPT ); Fri, 17 Mar 2017 14:51:09 -0400 Received: from ale.deltatee.com ([207.54.116.67]:56541 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751309AbdCQSua (ORCPT ); Fri, 17 Mar 2017 14:50:30 -0400 Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1cowvs-0002ZF-Se; Fri, 17 Mar 2017 12:49:04 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.84_2) (envelope-from ) id 1cowvp-0000qL-Pz; Fri, 17 Mar 2017 12:48:57 -0600 From: Logan Gunthorpe To: Greg Kroah-Hartman , Dan Williams , Hans Verkuil , Alexander Viro , Alexandre Belloni , Jason Gunthorpe , Johannes Thumshirn , Dmitry Torokhov , Linus Walleij , Jarkko Sakkinen , "James E.J. Bottomley" , "Martin K. Petersen" , David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Cyrille Pitchen Cc: linux-pci@vger.kernel.org, linux-scsi@vger.kernel.org, rtc-linux@googlegroups.com, linux-mtd@lists.infradead.org, linux-media@vger.kernel.org, linux-iio@vger.kernel.org, linux-rdma@vger.kernel.org, linux-gpio@vger.kernel.org, linux-input@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Logan Gunthorpe Date: Fri, 17 Mar 2017 12:48:15 -0600 Message-Id: <1489776503-3151-9-git-send-email-logang@deltatee.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1489776503-3151-1-git-send-email-logang@deltatee.com> References: <1489776503-3151-1-git-send-email-logang@deltatee.com> X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: gregkh@linuxfoundation.org, dan.j.williams@intel.com, hans.verkuil@cisco.com, viro@zeniv.linux.org.uk, jgunthorpe@obsidianresearch.com, jthumshirn@suse.de, linus.walleij@linaro.org, jarkko.sakkinen@linux.intel.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com, dwmw2@infradead.org, alexandre.belloni@free-electrons.com, boris.brezillon@free-electrons.com, dmitry.torokhov@gmail.com, computersforpeace@gmail.com, marek.vasut@gmail.com, cyrille.pitchen@atmel.com, rtc-linux@googlegroups.com, linux-mtd@lists.infradead.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, linux-scsi@vger.kernel.org, linux-media@vger.kernel.org, linux-iio@vger.kernel.org, linux-rdma@vger.kernel.org, linux-gpio@vger.kernel.org, linux-input@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on ale.deltatee.com X-Spam-Level: X-Spam-Status: No, score=-8.5 required=5.0 tests=ALL_TRUSTED,BAYES_00, GREYLIST_ISWHITE, MYRULES_FREE, MYRULES_NO_TEXT, RP_MATCHES_RCVD autolearn=ham autolearn_force=no version=3.4.0 Subject: [PATCH v5 08/16] IB/ucm: utilize new cdev_device_add helper function X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Jason Gunthorpe The use after free is not triggerable here because the cdev holds the module lock and the only device_unregister is only triggered by module unload, however make the change for consistency. To make this work the cdev_del needs to move out of the struct device release function. This cleans up the error path significantly and thus also fixes a minor bug where the devnum would not be released if cdev_add failed. Signed-off-by: Jason Gunthorpe Signed-off-by: Logan Gunthorpe Reviewed-by: Logan Gunthorpe Reviewed-by: Leon Romanovsky --- drivers/infiniband/core/ucm.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c index cc0d51f..d15efa4 100644 --- a/drivers/infiniband/core/ucm.c +++ b/drivers/infiniband/core/ucm.c @@ -1205,12 +1205,15 @@ static void ib_ucm_release_dev(struct device *dev) struct ib_ucm_device *ucm_dev; ucm_dev = container_of(dev, struct ib_ucm_device, dev); - cdev_del(&ucm_dev->cdev); + kfree(ucm_dev); +} + +static void ib_ucm_free_dev(struct ib_ucm_device *ucm_dev) +{ if (ucm_dev->devnum < IB_UCM_MAX_DEVICES) clear_bit(ucm_dev->devnum, dev_map); else clear_bit(ucm_dev->devnum - IB_UCM_MAX_DEVICES, overflow_map); - kfree(ucm_dev); } static const struct file_operations ucm_fops = { @@ -1266,7 +1269,9 @@ static void ib_ucm_add_one(struct ib_device *device) if (!ucm_dev) return; + device_initialize(&ucm_dev->dev); ucm_dev->ib_dev = device; + ucm_dev->dev.release = ib_ucm_release_dev; devnum = find_first_zero_bit(dev_map, IB_UCM_MAX_DEVICES); if (devnum >= IB_UCM_MAX_DEVICES) { @@ -1286,16 +1291,14 @@ static void ib_ucm_add_one(struct ib_device *device) cdev_init(&ucm_dev->cdev, &ucm_fops); ucm_dev->cdev.owner = THIS_MODULE; kobject_set_name(&ucm_dev->cdev.kobj, "ucm%d", ucm_dev->devnum); - if (cdev_add(&ucm_dev->cdev, base, 1)) - goto err; ucm_dev->dev.class = &cm_class; ucm_dev->dev.parent = device->dev.parent; - ucm_dev->dev.devt = ucm_dev->cdev.dev; - ucm_dev->dev.release = ib_ucm_release_dev; + ucm_dev->dev.devt = base; + dev_set_name(&ucm_dev->dev, "ucm%d", ucm_dev->devnum); - if (device_register(&ucm_dev->dev)) - goto err_cdev; + if (cdev_device_add(&ucm_dev->cdev, &ucm_dev->dev)) + goto err_devnum; if (device_create_file(&ucm_dev->dev, &dev_attr_ibdev)) goto err_dev; @@ -1304,15 +1307,11 @@ static void ib_ucm_add_one(struct ib_device *device) return; err_dev: - device_unregister(&ucm_dev->dev); -err_cdev: - cdev_del(&ucm_dev->cdev); - if (ucm_dev->devnum < IB_UCM_MAX_DEVICES) - clear_bit(devnum, dev_map); - else - clear_bit(devnum, overflow_map); + cdev_device_del(&ucm_dev->cdev, &ucm_dev->dev); +err_devnum: + ib_ucm_free_dev(ucm_dev); err: - kfree(ucm_dev); + put_device(&ucm_dev->dev); return; } @@ -1323,7 +1322,9 @@ static void ib_ucm_remove_one(struct ib_device *device, void *client_data) if (!ucm_dev) return; - device_unregister(&ucm_dev->dev); + cdev_device_del(&ucm_dev->cdev, &ucm_dev->dev); + ib_ucm_free_dev(ucm_dev); + put_device(&ucm_dev->dev); } static CLASS_ATTR_STRING(abi_version, S_IRUGO,