Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932118AbdIGLYs (ORCPT ); Thu, 7 Sep 2017 07:24:48 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:37228 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932070AbdIGLYo (ORCPT ); Thu, 7 Sep 2017 07:24:44 -0400 X-Google-Smtp-Source: ADKCNb5Zdj/5ge/pUSW/07OJYTfgQagghqpCraOw2Bz7Z+pPLVlppxtZK4Q42ShHeWsKj4z6+w3Rng== From: Jan Glauber To: Ulf Hansson Cc: David Daney , linux-mmc@vger.kernel.org, Rob Herring , linux-kernel@vger.kernel.org, Jan Glauber Subject: [PATCH] mmc: cavium: Fix use-after-free in of_platform_device_destroy Date: Thu, 7 Sep 2017 13:24:17 +0200 Message-Id: <20170907112417.21495-1-jglauber@cavium.com> X-Mailer: git-send-email 2.9.0.rc0.21.g7777322 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3315 Lines: 77 KASAN reported the following: [ 19.338655] ================================================================== [ 19.345946] BUG: KASAN: use-after-free in of_platform_device_destroy+0x88/0x100 [ 19.345966] Read of size 8 at addr fffffe01aa6f1468 by task systemd-udevd/264 [ 19.345983] CPU: 1 PID: 264 Comm: systemd-udevd Not tainted 4.13.0-jang+ #737 [ 19.345989] Hardware name: Cavium ThunderX CN81XX board (DT) [ 19.345995] Call trace: [ 19.346013] [] dump_backtrace+0x0/0x368 [ 19.346026] [] show_stack+0x24/0x30 [ 19.346040] [] dump_stack+0xa4/0xc8 [ 19.346057] [] print_address_description+0x68/0x258 [ 19.346070] [] kasan_report+0x238/0x2f8 [ 19.346082] [] __asan_load8+0x88/0xb8 [ 19.346098] [] of_platform_device_destroy+0x88/0x100 [ 19.346131] [] thunder_mmc_probe+0x314/0x550 [thunderx_mmc] [ 19.346147] [] pci_device_probe+0x158/0x1f8 [ 19.346162] [] driver_probe_device+0x394/0x5f8 [ 19.346174] [] __driver_attach+0x154/0x158 [ 19.346185] [] bus_for_each_dev+0xdc/0x140 [ 19.346196] [] driver_attach+0x38/0x48 [ 19.346207] [] bus_add_driver+0x290/0x3c8 [ 19.346219] [] driver_register+0xbc/0x1a0 [ 19.346232] [] __pci_register_driver+0xc4/0xd8 [ 19.346260] [] thunder_mmc_driver_init+0x24/0x10000 [thunderx_mmc] [ 19.346273] [] do_one_initcall+0x98/0x1c0 [ 19.346289] [] do_init_module+0xe0/0x2cc [ 19.346303] [] load_module+0x3238/0x35c0 [ 19.346318] [] SyS_finit_module+0x190/0x1a0 [ 19.346329] [] __sys_trace_return+0x0/0x4 This is caused by: platform_device_register() -> platform_device_unregister(to_platform_device(dev)) freeing struct device -> of_node_clear_flag(dev->of_node, ...) writing to the freed device The issue is solved by increasing the reference count before calling of_platform_device_destroy() so freeing the device is postponed after the call. Fixes: 8fb83b142823 ("mmc: cavium: Fix probing race with regulator") Signed-off-by: Jan Glauber --- drivers/mmc/host/cavium-thunderx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/cavium-thunderx.c b/drivers/mmc/host/cavium-thunderx.c index b9cc95998799..eee08d81b242 100644 --- a/drivers/mmc/host/cavium-thunderx.c +++ b/drivers/mmc/host/cavium-thunderx.c @@ -7,6 +7,7 @@ * * Copyright (C) 2016 Cavium Inc. */ +#include #include #include #include @@ -149,8 +150,11 @@ static int thunder_mmc_probe(struct pci_dev *pdev, for (i = 0; i < CAVIUM_MAX_MMC; i++) { if (host->slot[i]) cvm_mmc_of_slot_remove(host->slot[i]); - if (host->slot_pdev[i]) + if (host->slot_pdev[i]) { + get_device(&host->slot_pdev[i]->dev); of_platform_device_destroy(&host->slot_pdev[i]->dev, NULL); + put_device(&host->slot_pdev[i]->dev); + } } clk_disable_unprepare(host->clk); return ret; -- 2.9.0.rc0.21.g7777322