From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB02DECDE46 for ; Mon, 22 Oct 2018 10:20:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64BEE20853 for ; Mon, 22 Oct 2018 10:20:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="loVxdehW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64BEE20853 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728893AbeJVSiB (ORCPT ); Mon, 22 Oct 2018 14:38:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:48906 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728144AbeJVSiA (ORCPT ); Mon, 22 Oct 2018 14:38:00 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E9BFC20853; Mon, 22 Oct 2018 10:20:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540203604; bh=key7R7mfhs0Nb7TnCMfJPXXuX7/OOMdvAw3NshCiPyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=loVxdehWBDMl5b1OlUKIk3PZpqlCB1nYLuCxZ40vNzjhaOuiHLnGvqvnstJLZl65T p47sP4cnoy36f28ZP3/1rCh4VSv9RwwhzO2A3u+FdZtXLcDOPYsyDBRVLhjtsBHhIZ T2l5lbYUdVBVEOmMnyuUeBLSTz4Ggh5oD7JA84nY= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Stephen Boyd , Evan Green , Thierry Reding , Grygorii Strashko , Linus Walleij , Sasha Levin Subject: [PATCH AUTOSEL 4.18 19/27] gpio: Assign gpio_irq_chip::parents to non-stack pointer Date: Mon, 22 Oct 2018 06:19:16 -0400 Message-Id: <20181022101924.40531-19-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181022101924.40531-1-sashal@kernel.org> References: <20181022101924.40531-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephen Boyd [ Upstream commit 3e779a2e7f909015f21428b66834127496110b6d ] gpiochip_set_cascaded_irqchip() is passed 'parent_irq' as an argument and then the address of that argument is assigned to the gpio chips gpio_irq_chip 'parents' pointer shortly thereafter. This can't ever work, because we've just assigned some stack address to a pointer that we plan to dereference later in gpiochip_irq_map(). I ran into this issue with the KASAN report below when gpiochip_irq_map() tried to setup the parent irq with a total junk pointer for the 'parents' array. BUG: KASAN: stack-out-of-bounds in gpiochip_irq_map+0x228/0x248 Read of size 4 at addr ffffffc0dde472e0 by task swapper/0/1 CPU: 7 PID: 1 Comm: swapper/0 Not tainted 4.14.72 #34 Call trace: [] dump_backtrace+0x0/0x718 [] show_stack+0x20/0x2c [] __dump_stack+0x20/0x28 [] dump_stack+0x80/0xbc [] print_address_description+0x70/0x238 [] kasan_report+0x1cc/0x260 [] __asan_report_load4_noabort+0x2c/0x38 [] gpiochip_irq_map+0x228/0x248 [] irq_domain_associate+0x114/0x2ec [] irq_create_mapping+0x120/0x234 [] irq_create_fwspec_mapping+0x4c8/0x88c [] irq_create_of_mapping+0x180/0x210 [] of_irq_get+0x138/0x198 [] spi_drv_probe+0x94/0x178 [] driver_probe_device+0x51c/0x824 [] __device_attach_driver+0x148/0x20c [] bus_for_each_drv+0x120/0x188 [] __device_attach+0x19c/0x2dc [] device_initial_probe+0x20/0x2c [] bus_probe_device+0x80/0x154 [] device_add+0x9b8/0xbdc [] spi_add_device+0x1b8/0x380 [] spi_register_controller+0x111c/0x1378 [] spi_geni_probe+0x4dc/0x6f8 [] platform_drv_probe+0xdc/0x130 [] driver_probe_device+0x51c/0x824 [] __driver_attach+0x100/0x194 [] bus_for_each_dev+0x104/0x16c [] driver_attach+0x48/0x54 [] bus_add_driver+0x274/0x498 [] driver_register+0x1ac/0x230 [] __platform_driver_register+0xcc/0xdc [] spi_geni_driver_init+0x1c/0x24 [] do_one_initcall+0x240/0x3dc [] kernel_init_freeable+0x378/0x468 [] kernel_init+0x14/0x110 [] ret_from_fork+0x10/0x18 The buggy address belongs to the page: page:ffffffbf037791c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x4000000000000000() raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff raw: ffffffbf037791e0 ffffffbf037791e0 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffffffc0dde47180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0dde47200: f1 f1 f1 f1 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f2 f2 >ffffffc0dde47280: f2 f2 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 ^ ffffffc0dde47300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0dde47380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Let's leave around one unsigned int in the gpio_irq_chip struct for the single parent irq case and repoint the 'parents' array at it. This way code is left mostly intact to setup parents and we waste an extra few bytes per structure of which there should be only a handful in a system. Cc: Evan Green Cc: Thierry Reding Cc: Grygorii Strashko Fixes: e0d897289813 ("gpio: Implement tighter IRQ chip integration") Signed-off-by: Stephen Boyd Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin --- drivers/gpio/gpiolib.c | 3 ++- include/linux/gpio/driver.h | 7 +++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 06dce16e22bb..70f0dedca59f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1675,7 +1675,8 @@ static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip, irq_set_chained_handler_and_data(parent_irq, parent_handler, gpiochip); - gpiochip->irq.parents = &parent_irq; + gpiochip->irq.parent_irq = parent_irq; + gpiochip->irq.parents = &gpiochip->irq.parent_irq; gpiochip->irq.num_parents = 1; } diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 5382b5183b7e..82a953ec5ef0 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -94,6 +94,13 @@ struct gpio_irq_chip { */ unsigned int num_parents; + /** + * @parent_irq: + * + * For use by gpiochip_set_cascaded_irqchip() + */ + unsigned int parent_irq; + /** * @parents: * -- 2.17.1