Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751408Ab3HSUhe (ORCPT ); Mon, 19 Aug 2013 16:37:34 -0400 Received: from mail-pd0-f172.google.com ([209.85.192.172]:40661 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133Ab3HSUhb (ORCPT ); Mon, 19 Aug 2013 16:37:31 -0400 Message-ID: <1376944647.5082.12.camel@chimera> Subject: [PATCH] Fix stack corruption on some architectures From: Daniel Gimpelevich To: Jan Dumon , Greg Kroah-Hartman , linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 19 Aug 2013 13:37:27 -0700 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2873 Lines: 76 There is no need to get an interface specification if we know it's the wrong one; trivial change. The big thing, though, was explained in the #mipslinux IRC channel: [Mon 2013-08-19 12:28:21 PM PDT] guys, are you sure it's not "DMA off stack" case? [Mon 2013-08-19 12:28:35 PM PDT] it's a known stack corruptor on non-coherent arches [Mon 2013-08-19 12:31:48 PM PDT] headless: for usb/ehci? [Mon 2013-08-19 12:34:11 PM PDT] headless: explain [Mon 2013-08-19 12:35:38 PM PDT] usb_control_msg() (or other such func) should not use buffer on stack. DMA from/to stack is prohibited [Mon 2013-08-19 12:35:58 PM PDT] and EHCI uses DMA on control xfers (as well as all the others) Signed-off-by: Daniel Gimpelevich --- drivers/net/usb/hso.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index cba1d46..86292e6 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2816,13 +2816,16 @@ exit: static int hso_get_config_data(struct usb_interface *interface) { struct usb_device *usbdev = interface_to_usbdev(interface); - u8 config_data[17]; + u8 *config_data = kmalloc(17, GFP_KERNEL); u32 if_num = interface->altsetting->desc.bInterfaceNumber; s32 result; + if (!config_data) + return -ENOMEM; if (usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x86, 0xC0, 0, 0, config_data, 17, USB_CTRL_SET_TIMEOUT) != 0x11) { + kfree(config_data); return -EIO; } @@ -2873,6 +2876,7 @@ static int hso_get_config_data(struct usb_interface *interface) if (config_data[16] & 0x1) result |= HSO_INFO_CRC_BUG; + kfree(config_data); return result; } @@ -2886,6 +2890,11 @@ static int hso_probe(struct usb_interface *interface, struct hso_shared_int *shared_int; struct hso_device *tmp_dev = NULL; + if (interface->cur_altsetting->desc.bInterfaceClass != 0xFF) { + dev_err(&interface->dev, "Not our interface\n"); + return -ENODEV; + } + if_num = interface->altsetting->desc.bInterfaceNumber; /* Get the interface/port specification from either driver_info or from @@ -2895,10 +2904,6 @@ static int hso_probe(struct usb_interface *interface, else port_spec = hso_get_config_data(interface); - if (interface->cur_altsetting->desc.bInterfaceClass != 0xFF) { - dev_err(&interface->dev, "Not our interface\n"); - return -ENODEV; - } /* Check if we need to switch to alt interfaces prior to port * configuration */ if (interface->num_altsetting > 1) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/