Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031512AbcCQWVu (ORCPT ); Thu, 17 Mar 2016 18:21:50 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35933 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755468AbcCQWVl (ORCPT ); Thu, 17 Mar 2016 18:21:41 -0400 From: Nicolai Stange To: Greg Kroah-Hartman Cc: Peter Chen , Philipp Zabel , Alan Stern , Rob Herring , Arnd Bergmann , Geliang Tang , Stefan Koch , Viresh Kumar , Tomeu Vizoso , Oliver Neukum , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolai Stange Subject: [PATCH] usb/core: usb_alloc_dev(): fix setting of ->portnum Date: Thu, 17 Mar 2016 23:21:28 +0100 Message-Id: <1458253288-5174-1-git-send-email-nicstange@gmail.com> X-Mailer: git-send-email 2.7.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4131 Lines: 107 With commit 69bec7259853 ("USB: core: let USB device know device node"), the port1 argument of usb_alloc_dev() gets overwritten as follows: ... usb_alloc_dev(..., unsigned port1) { ... if (!parent->parent) { port1 = usb_hcd_find_raw_port_number(..., port1); } ... } Later on, this now overwritten port1 gets assigned to ->portnum: dev->portnum = port1; However, since xhci_find_raw_port_number() isn't idempotent, the aforementioned commit causes a number of KASAN splats like the following: BUG: KASAN: slab-out-of-bounds in xhci_find_raw_port_number+0x98/0x170 at addr ffff8801d9311670 Read of size 8 by task kworker/2:1/87 [...] Workqueue: usb_hub_wq hub_event 0000000000000188 000000005814b877 ffff8800cba17588 ffffffff8191447e 0000000041b58ab3 ffffffff82a03209 ffffffff819143a2 ffffffff82a252f4 ffff8801d93115e0 0000000000000188 ffff8801d9311628 ffff8800cba17588 Call Trace: [] dump_stack+0xdc/0x15e [] ? _atomic_dec_and_lock+0xa2/0xa2 [] ? print_section+0x61/0xb0 [] print_trailer+0x179/0x2c0 [] object_err+0x34/0x40 [] kasan_report_error+0x2f8/0x8b0 [] ? __slab_alloc+0x5e/0x90 [] ? __lock_is_held+0x90/0x130 [] kasan_report+0x71/0xa0 [] ? kmem_cache_alloc_trace+0x212/0x560 [] ? xhci_find_raw_port_number+0x98/0x170 [] __asan_load8+0x64/0x70 [] xhci_find_raw_port_number+0x98/0x170 [] xhci_setup_addressable_virt_dev+0x235/0xa10 [] xhci_setup_device+0x3c1/0x1430 [] ? trace_hardirqs_on+0xd/0x10 [] ? xhci_setup_device+0x1430/0x1430 [] xhci_address_device+0x13/0x20 [] hub_port_init+0x55a/0x1550 [] hub_event+0xef5/0x24d0 [] ? hub_port_debounce+0x2f0/0x2f0 [] ? debug_object_deactivate+0x1be/0x270 [] ? print_rt_rq+0x53/0x2d0 [] ? trace_hardirqs_off+0xd/0x10 [] ? _raw_spin_unlock_irqrestore+0x5b/0x60 [] ? irq_domain_set_hwirq_and_chip+0x30/0xb0 [] ? debug_lockdep_rcu_enabled+0x39/0x40 [] ? __lock_is_held+0x90/0x130 [] process_one_work+0x567/0xec0 [...] Afterwards, xhci reports some functional errors: xhci_hcd 0000:00:14.0: ERROR: unexpected setup address command completion code 0x11. xhci_hcd 0000:00:14.0: ERROR: unexpected setup address command completion code 0x11. usb 4-3: device not accepting address 2, error -22 Fix this by not overwriting the port1 argument in usb_alloc_dev(), but storing the raw port number as required by OF in an additional variable, raw_port. Fixes: 69bec7259853 ("USB: core: let USB device know device node") Signed-off-by: Nicolai Stange --- Applicable to linux-next-20160317 drivers/usb/core/usb.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index ffa5cf1..6b4fc16 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -424,6 +424,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, struct usb_device *dev; struct usb_hcd *usb_hcd = bus_to_hcd(bus); unsigned root_hub = 0; + unsigned raw_port; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) @@ -498,11 +499,11 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, if (!parent->parent) { /* device under root hub's port */ - port1 = usb_hcd_find_raw_port_number(usb_hcd, + raw_port = usb_hcd_find_raw_port_number(usb_hcd, port1); } dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node, - port1); + raw_port); /* hub driver sets up TT records */ } -- 2.7.2