From patchwork Wed Nov 11 19:07:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 11898343 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 DD2F21746 for ; Wed, 11 Nov 2020 19:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C549F206F1 for ; Wed, 11 Nov 2020 19:09:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725860AbgKKTJl (ORCPT ); Wed, 11 Nov 2020 14:09:41 -0500 Received: from mailout3.hostsharing.net ([176.9.242.54]:39181 "EHLO mailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726101AbgKKTJk (ORCPT ); Wed, 11 Nov 2020 14:09:40 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (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 5F191101E69A6; Wed, 11 Nov 2020 20:09:38 +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 2B7B060E6357; Wed, 11 Nov 2020 20:09:38 +0100 (CET) X-Mailbox-Line: From ad66e0a0ad96feb848814842ecf5b6a4539ef35c Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Wed, 11 Nov 2020 20:07:20 +0100 Subject: [PATCH 2/4] spi: bcm2835: 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 bcm2835_spi_remove() accesses the driver's private data after calling spi_unregister_controller() even though that function releases the last reference on the spi_controller 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: f8043872e796 ("spi: add driver for BCM2835") Reported-by: Sascha Hauer Reported-by: Florian Fainelli Signed-off-by: Lukas Wunner Cc: # v3.10+: 123456789abc: spi: Introduce device-managed SPI controller allocation Cc: # v3.10+ Cc: Vladimir Oltean Tested-by: Florian Fainelli Acked-by: Florian Fainelli --- drivers/spi/spi-bcm2835.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 7104cf17b848..197485f2c2b2 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1278,7 +1278,7 @@ static int bcm2835_spi_probe(struct platform_device *pdev) struct bcm2835_spi *bs; int err; - ctlr = spi_alloc_master(&pdev->dev, ALIGN(sizeof(*bs), + ctlr = devm_spi_alloc_master(&pdev->dev, ALIGN(sizeof(*bs), dma_get_cache_alignment())); if (!ctlr) return -ENOMEM; @@ -1299,23 +1299,17 @@ static int bcm2835_spi_probe(struct platform_device *pdev) bs->ctlr = ctlr; bs->regs = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(bs->regs)) { - err = PTR_ERR(bs->regs); - goto out_controller_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 = dev_err_probe(&pdev->dev, PTR_ERR(bs->clk), - "could not get clk\n"); - goto out_controller_put; - } + if (IS_ERR(bs->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(bs->clk), + "could not get clk\n"); bs->irq = platform_get_irq(pdev, 0); - if (bs->irq <= 0) { - err = bs->irq ? bs->irq : -ENODEV; - goto out_controller_put; - } + if (bs->irq <= 0) + return bs->irq ? bs->irq : -ENODEV; clk_prepare_enable(bs->clk); @@ -1349,8 +1343,6 @@ static int bcm2835_spi_probe(struct platform_device *pdev) bcm2835_dma_release(ctlr, bs); out_clk_disable: clk_disable_unprepare(bs->clk); -out_controller_put: - spi_controller_put(ctlr); return err; }