From patchwork Fri Mar 17 18:48:09 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 740449 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vlDvM5J5wz9ryr for ; Sat, 18 Mar 2017 05:51:11 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="g680/HGM"; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=infradead.org header.i=@infradead.org header.b="WaKjT7vM"; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Subject:References: In-Reply-To:Message-Id:Date:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6TYFAUqObhQU5mzpkFWJzgMaIftv8juOB9C2L6zu+IQ=; b=g680/HGMmfX9Uy TJuNZctKHejvdu/aEX1G1WwY0LO801+x+iAjqFmTDqSdZQY/nGONmhfwmcsq3enX5YzzyUZhWLWuM ujTwIP1DTCLrLfet2lOaZSauK1TOGWUFRouCwArA8C97nKoaE2NZ7ejo2hjLjI+NvQykL+0KrWQzt dg7D5j/xOESTsgmfng0QMAJBiuwNe+f6ihWuyQVspLnUNkAxC8ziXZMm8R1GM0fDWsTW3U7b9AwX6 UIVyOQPIwE1rZ8u7S4czCTHmCqG4fGa3weJO1YZgryhQceXTKcJWKmGjC0Ow4yayILYF1DzJx8WNS CW/QgxxwFEoYCroXnu3w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1cowxs-0004kC-6E; Fri, 17 Mar 2017 18:51:04 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cowx0-0003j2-R5 for linux-mtd@bombadil.infradead.org; Fri, 17 Mar 2017 18:50:10 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Subject:References:In-Reply-To: Message-Id:Date:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=mpY/zQ+moaobGmqdCDKCwBKfBBxawLIVE3N4YLQmzLo=; b=WaKjT7vM9gcIsRLByuIdNy/ZL rTngdyLoJGztlQkdrGMOgM9KJkQrIK6Xp9YNB8E1HHY8Y9XTdns3WRbeC4fysCx9Yeme3h6TGm237 UTbV2gyRkzj03DOY8ag6iDOywiKqxrdeggAIIeti8YJvt5QeSfIfxABDG5Mzk6LZlizQI9C0XnmxO wluaYlFwE1KQK0DKsFtUYL/RqTMP8NJ9yITLQhGXnZdQsiydXE47kLW9EDjuDTRczeeCrEMJUvQxP EPjYCMSwmsvBdSKrrCcr01gv6qVL2UX4zGH3YjwX8+kmNjJI0v9l/5yiG6yRcPehcvC7Y61g3kPMh oL+H0doJw==; Received: from ale.deltatee.com ([207.54.116.67]) by merlin.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cowwx-0007Yt-LL for linux-mtd@lists.infradead.org; Fri, 17 Mar 2017 18:50:09 +0000 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-0002Z9-Sh; Fri, 17 Mar 2017 12:49:06 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.84_2) (envelope-from ) id 1cowvp-0000pr-4U; 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 Date: Fri, 17 Mar 2017 12:48:09 -0600 Message-Id: <1489776503-3151-3-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, stable@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 02/16] device-dax: fix cdev leak 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) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170317_145008_116454_01410DA2 X-CRM114-Status: GOOD ( 12.23 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.4.1 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-scsi@vger.kernel.org, rtc-linux@googlegroups.com, linux-gpio@vger.kernel.org, linux-iio@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-rdma@vger.kernel.org, linux-mtd@lists.infradead.org, linux-input@vger.kernel.org, linux-fsdevel@vger.kernel.org, Logan Gunthorpe , linux-media@vger.kernel.org MIME-Version: 1.0 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Dan Williams If device_add() fails, cleanup the cdev. Otherwise, we leak a kobj_map() with a stale device number. As Jason points out, there is a small possibility that userspace has opened and mapped the device in the time between cdev_add() and the device_add() failure. We need a new kill_dax_dev() helper to invalidate any established mappings. Fixes: ba09c01d2fa8 ("dax: convert to the cdev api") Cc: Reported-by: Jason Gunthorpe Signed-off-by: Dan Williams Signed-off-by: Logan Gunthorpe Reviewed-by: Johannes Thumshirn --- drivers/dax/dax.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index 8d9829f..a5ed59a 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/dax.c @@ -675,13 +675,10 @@ static void dax_dev_release(struct device *dev) kfree(dax_dev); } -static void unregister_dax_dev(void *dev) +static void kill_dax_dev(struct dax_dev *dax_dev) { - struct dax_dev *dax_dev = to_dax_dev(dev); struct cdev *cdev = &dax_dev->cdev; - dev_dbg(dev, "%s\n", __func__); - /* * Note, rcu is not protecting the liveness of dax_dev, rcu is * ensuring that any fault handlers that might have seen @@ -693,6 +690,15 @@ static void unregister_dax_dev(void *dev) synchronize_rcu(); unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1); cdev_del(cdev); +} + +static void unregister_dax_dev(void *dev) +{ + struct dax_dev *dax_dev = to_dax_dev(dev); + + dev_dbg(dev, "%s\n", __func__); + + kill_dax_dev(dax_dev); device_unregister(dev); } @@ -769,6 +775,7 @@ struct dax_dev *devm_create_dax_dev(struct dax_region *dax_region, dev_set_name(dev, "dax%d.%d", dax_region->id, dax_dev->id); rc = device_add(dev); if (rc) { + kill_dax_dev(dax_dev); put_device(dev); return ERR_PTR(rc); }