From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:52677 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934992AbcIEQvo (ORCPT ); Mon, 5 Sep 2016 12:51:44 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Lin , Mathias Nyman Subject: [PATCH 4.4 046/113] usb: xhci: Fix panic if disconnect Date: Mon, 5 Sep 2016 18:44:09 +0200 Message-Id: <20160905164351.169709054@linuxfoundation.org> In-Reply-To: <20160905164349.217621339@linuxfoundation.org> References: <20160905164349.217621339@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jim Lin commit 88716a93766b8f095cdef37a8e8f2c93aa233b21 upstream. After a device is disconnected, xhci_stop_device() will be invoked in xhci_bus_suspend(). Also the "disconnect" IRQ will have ISR to invoke xhci_free_virt_device() in this sequence. xhci_irq -> xhci_handle_event -> handle_cmd_completion -> xhci_handle_cmd_disable_slot -> xhci_free_virt_device If xhci->devs[slot_id] has been assigned to NULL in xhci_free_virt_device(), then virt_dev->eps[i].ring in xhci_stop_device() may point to an invlid address to cause kernel panic. virt_dev = xhci->devs[slot_id]; : if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue) [] Unable to handle kernel paging request at virtual address 00001a68 [] pgd=ffffffc001430000 [] [00001a68] *pgd=000000013c807003, *pud=000000013c807003, *pmd=000000013c808003, *pte=0000000000000000 [] Internal error: Oops: 96000006 [#1] PREEMPT SMP [] CPU: 0 PID: 39 Comm: kworker/0:1 Tainted: G U [] Workqueue: pm pm_runtime_work [] task: ffffffc0bc0e0bc0 ti: ffffffc0bc0ec000 task.ti: ffffffc0bc0ec000 [] PC is at xhci_stop_device.constprop.11+0xb4/0x1a4 This issue is found when running with realtek ethernet device (0bda:8153). Signed-off-by: Jim Lin Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-hub.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -377,6 +377,9 @@ static int xhci_stop_device(struct xhci_ ret = 0; virt_dev = xhci->devs[slot_id]; + if (!virt_dev) + return -ENODEV; + cmd = xhci_alloc_command(xhci, false, true, GFP_NOIO); if (!cmd) { xhci_dbg(xhci, "Couldn't allocate command structure.\n");