From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33156 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729972AbeJBUMy (ORCPT ); Tue, 2 Oct 2018 16:12:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Harry Pan , Kai-Heng Feng Subject: [PATCH 4.18 151/228] usb: core: safely deal with the dynamic quirk lists Date: Tue, 2 Oct 2018 06:24:08 -0700 Message-Id: <20181002132509.315095917@linuxfoundation.org> In-Reply-To: <20181002132459.032960735@linuxfoundation.org> References: <20181002132459.032960735@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Harry Pan commit 16c4cb19fa85c648a803752eb63cac0ef69231c2 upstream. 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 Acked-by: Kai-Heng Feng Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/quirks.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -58,6 +58,7 @@ static int quirks_param_set(const char * 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 = 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.