From patchwork Fri Aug 2 15:00:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 11073713 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0554C912 for ; Fri, 2 Aug 2019 14:59:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E834B28564 for ; Fri, 2 Aug 2019 14:59:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DB55028740; Fri, 2 Aug 2019 14:59:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7FBA328564 for ; Fri, 2 Aug 2019 14:59:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395078AbfHBO7F (ORCPT ); Fri, 2 Aug 2019 10:59:05 -0400 Received: from mga06.intel.com ([134.134.136.31]:55329 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726505AbfHBO7F (ORCPT ); Fri, 2 Aug 2019 10:59:05 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Aug 2019 07:59:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,338,1559545200"; d="scan'208";a="167253792" Received: from mattu-haswell.fi.intel.com ([10.237.72.164]) by orsmga008.jf.intel.com with ESMTP; 02 Aug 2019 07:59:03 -0700 From: Mathias Nyman To: Cc: , eballetbo@gmail.com, Mathias Nyman Subject: [PATCH] xhci: Fix NULL pointer dereference at endpoint zero reset. Date: Fri, 2 Aug 2019 18:00:44 +0300 Message-Id: <1564758044-24748-1-git-send-email-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Usb core will reset the default control endpoint "ep0" before resetting a device. if the endpoint has a valid pointer back to the usb device then the xhci driver reset callback will try to clear the toggle for the endpoint. ep0 didn't use to have this pointer set as ep0 was always allocated by default together with a xhci slot for the usb device. Other endpoints got their usb device pointer set in xhci_add_endpoint() This changed with commit ef513be0a905 ("usb: xhci: Add Clear_TT_Buffer") which sets the pointer for any endpoint on a FS/LS device behind a HS hub that halts, including ep0. If xHC controller needs to be reset at resume, then all the xhci slots will be lost. Slots will be reenabled and reallocated at device reset, but unlike other endpoints the ep0 is reset before device reset, while the xhci slot may still be invalid, causing NULL pointer dereference. Fix it by checking that the endpoint has both a usb device pointer and valid xhci slot before trying to clear the toggle. This issue was not seen earlier as ep0 didn't use to have a valid usb device pointer, and other endpoints were only reset after device reset when xhci slots were properly reenabled. Reported-by: Bob Gleitsmann Reported-by: Enric Balletbo Serra Fixes: ef513be0a905 ("usb: xhci: Add Clear_TT_Buffer") Signed-off-by: Mathias Nyman Tested-by: Enric Balletbo i Serra --- drivers/usb/host/xhci.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 248cd7a..03d1e55 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3089,8 +3089,18 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd, return; udev = (struct usb_device *) host_ep->hcpriv; vdev = xhci->devs[udev->slot_id]; + + /* + * vdev may be lost due to xHC restore error and re-initialization + * during S3/S4 resume. A new vdev will be allocated later by + * xhci_discover_or_reset_device() + */ + if (!udev->slot_id || !vdev) + return; ep_index = xhci_get_endpoint_index(&host_ep->desc); ep = &vdev->eps[ep_index]; + if (!ep) + return; /* Bail out if toggle is already being cleared by a endpoint reset */ if (ep->ep_state & EP_HARD_CLEAR_TOGGLE) {