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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 D1E30FC6182 for ; Fri, 14 Sep 2018 12:36:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E04B20881 for ; Fri, 14 Sep 2018 12:36:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E04B20881 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com 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 S1728183AbeINRuu (ORCPT ); Fri, 14 Sep 2018 13:50:50 -0400 Received: from [101.8.162.226] ([101.8.162.226]:15824 "EHLO E6440.gar.corp.intel.com" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727803AbeINRuu (ORCPT ); Fri, 14 Sep 2018 13:50:50 -0400 X-Greylist: delayed 4042 seconds by postgrey-1.27 at vger.kernel.org; Fri, 14 Sep 2018 13:50:50 EDT Received: from E6440.gar.corp.intel.com (localhost [127.0.0.1]) by E6440.gar.corp.intel.com (Postfix) with ESMTP id 1F031C23C1; Fri, 14 Sep 2018 16:58:19 +0800 (CST) From: Harry Pan To: LKML Cc: gs0622@gmail.com, jongpil19.jung@samsung.com, rajatja@chromium.org, Harry Pan , gregkh@linuxfoundation.org, kai.heng.feng@canonical.com, stern@rowland.harvard.edu, felipe.balbi@linux.intel.com, snecknico@gmail.com, jackstocker.93@gmail.com, oneukum@suse.com, linux-usb@vger.kernel.org Subject: [PATCH] usb: core: safely deal with the dynamic quirk lists Date: Fri, 14 Sep 2018 16:58:16 +0800 Message-Id: <20180914085816.10888-1-harry.pan@intel.com> X-Mailer: git-send-email 2.16.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Applying dynamic usbcore quirks in early booting when the slab is not yet ready would cause kernel panic of null pointer dereference because the quirk_count has been counted as 1 while the quirk_list was failed to allocate. i.e., [ 1.044970] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1.044995] IP: [] usb_detect_quirks+0x88/0xd1 [ 1.045016] PGD 0 [ 1.045026] Oops: 0000 [#1] PREEMPT SMP [ 1.046986] gsmi: Log Shutdown Reason 0x03 [ 1.046995] Modules linked in: [ 1.047008] CPU: 0 PID: 81 Comm: kworker/0:3 Not tainted 4.4.154 #28 [ 1.047016] Hardware name: Google Coral/Coral, BIOS Google_Coral.10068.27.0 12/04/2017 [ 1.047028] Workqueue: usb_hub_wq hub_event [ 1.047037] task: ffff88017a321c80 task.stack: ffff88017a384000 [ 1.047044] RIP: 0010:[] [] usb_detect_quirks+0x88/0xd1 To tackle this odd, let's balance the quirk_count to 0 when the kcalloc call fails, and defer the quirk setting into a lower level callback which ensures that the kernel memory management has been initialized. Fixes: 027bd6cafd9a ("usb: core: Add "quirks" parameter for usbcore") Signed-off-by: Harry Pan --- drivers/usb/core/quirks.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index 097057d2eacf..1fe9843fb9c8 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -58,6 +58,7 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp) quirk_list = kcalloc(quirk_count, sizeof(struct quirk_entry), GFP_KERNEL); if (!quirk_list) { + quirk_count = 0; mutex_unlock(&quirk_mutex); return -ENOMEM; } @@ -154,7 +155,7 @@ static struct kparam_string quirks_param_string = { .string = quirks_param, }; -module_param_cb(quirks, &quirks_param_ops, &quirks_param_string, 0644); +device_param_cb(quirks, &quirks_param_ops, &quirks_param_string, 0644); MODULE_PARM_DESC(quirks, "Add/modify USB quirks by specifying quirks=vendorID:productID:quirks"); /* Lists of quirky USB devices, split in device quirks and interface quirks. -- 2.16.4