From patchwork Wed Nov 11 19:07:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 11898347 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CE34915E6 for ; Wed, 11 Nov 2020 19:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B44FE206F1 for ; Wed, 11 Nov 2020 19:10:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726201AbgKKTKr (ORCPT ); Wed, 11 Nov 2020 14:10:47 -0500 Received: from mailout3.hostsharing.net ([176.9.242.54]:34937 "EHLO mailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726036AbgKKTKq (ORCPT ); Wed, 11 Nov 2020 14:10:46 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by mailout3.hostsharing.net (Postfix) with ESMTPS id 5355B101E69A6; Wed, 11 Nov 2020 20:10:44 +0100 (CET) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 200DB60E6357; Wed, 11 Nov 2020 20:10:44 +0100 (CET) X-Mailbox-Line: From b290b06357d0c0bdee9cecc539b840a90630f101 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Wed, 11 Nov 2020 20:07:30 +0100 Subject: [PATCH 3/4] spi: bcm2835aux: Fix use-after-free on unbind To: Mark Brown , Florian Fainelli Cc: linux-spi@vger.kernel.org, Vladimir Oltean , Sascha Hauer , "Nicolas Saenz Julienne" Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org bcm2835aux_spi_remove() accesses the driver's private data after calling spi_unregister_master() even though that function releases the last reference on the spi_master and thereby frees the private data. Fix by switching over to the new devm_spi_alloc_master() helper which keeps the private data accessible until the driver has unbound. Fixes: b9dd3f6d4172 ("spi: bcm2835aux: Fix controller unregister order") Signed-off-by: Lukas Wunner Cc: # v4.4+: 123456789abc: spi: Introduce device-managed SPI controller allocation Cc: # v4.4+: b9dd3f6d4172: spi: bcm2835aux: Fix controller unregister order Cc: # v4.4+ --- drivers/spi/spi-bcm2835aux.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c index 03b034c15d2b..fd58547110e6 100644 --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -494,7 +494,7 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev) unsigned long clk_hz; int err; - master = spi_alloc_master(&pdev->dev, sizeof(*bs)); + master = devm_spi_alloc_master(&pdev->dev, sizeof(*bs)); if (!master) return -ENOMEM; @@ -524,29 +524,24 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev) /* the main area */ bs->regs = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(bs->regs)) { - err = PTR_ERR(bs->regs); - goto out_master_put; - } + if (IS_ERR(bs->regs)) + return PTR_ERR(bs->regs); bs->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(bs->clk)) { - err = PTR_ERR(bs->clk); dev_err(&pdev->dev, "could not get clk: %d\n", err); - goto out_master_put; + return PTR_ERR(bs->clk); } bs->irq = platform_get_irq(pdev, 0); - if (bs->irq <= 0) { - err = bs->irq ? bs->irq : -ENODEV; - goto out_master_put; - } + if (bs->irq <= 0) + return bs->irq ? bs->irq : -ENODEV; /* this also enables the HW block */ err = clk_prepare_enable(bs->clk); if (err) { dev_err(&pdev->dev, "could not prepare clock: %d\n", err); - goto out_master_put; + return err; } /* just checking if the clock returns a sane value */ @@ -581,8 +576,6 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev) out_clk_disable: clk_disable_unprepare(bs->clk); -out_master_put: - spi_master_put(master); return err; }