Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932473AbcDZXfp (ORCPT ); Tue, 26 Apr 2016 19:35:45 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41286 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755112AbcDZXfH (ORCPT ); Tue, 26 Apr 2016 19:35:07 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Vladis Dronov" , "Dmitry Torokhov" , "Ralf Spenneberg" Date: Wed, 27 Apr 2016 01:02:24 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 055/115] Input: ati_remote2 - fix crashes on detecting device with invalid descriptor In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8426:ae4:c500:9cba:69ae:962d:6167 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3038 Lines: 106 3.2.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Vladis Dronov commit 950336ba3e4a1ffd2ca60d29f6ef386dd2c7351d upstream. The ati_remote2 driver expects at least two interfaces with one endpoint each. If given malicious descriptor that specify one interface or no endpoints, it will crash in the probe function. Ensure there is at least two interfaces and one endpoint for each interface before using it. The full disclosure: http://seclists.org/bugtraq/2016/Mar/90 Reported-by: Ralf Spenneberg Signed-off-by: Vladis Dronov Signed-off-by: Dmitry Torokhov Signed-off-by: Ben Hutchings --- drivers/input/misc/ati_remote2.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) --- a/drivers/input/misc/ati_remote2.c +++ b/drivers/input/misc/ati_remote2.c @@ -814,26 +814,49 @@ static int ati_remote2_probe(struct usb_ ar2->udev = udev; + /* Sanity check, first interface must have an endpoint */ + if (alt->desc.bNumEndpoints < 1 || !alt->endpoint) { + dev_err(&interface->dev, + "%s(): interface 0 must have an endpoint\n", __func__); + r = -ENODEV; + goto fail1; + } ar2->intf[0] = interface; ar2->ep[0] = &alt->endpoint[0].desc; + /* Sanity check, the device must have two interfaces */ ar2->intf[1] = usb_ifnum_to_if(udev, 1); + if ((udev->actconfig->desc.bNumInterfaces < 2) || !ar2->intf[1]) { + dev_err(&interface->dev, "%s(): need 2 interfaces, found %d\n", + __func__, udev->actconfig->desc.bNumInterfaces); + r = -ENODEV; + goto fail1; + } + r = usb_driver_claim_interface(&ati_remote2_driver, ar2->intf[1], ar2); if (r) goto fail1; + + /* Sanity check, second interface must have an endpoint */ alt = ar2->intf[1]->cur_altsetting; + if (alt->desc.bNumEndpoints < 1 || !alt->endpoint) { + dev_err(&interface->dev, + "%s(): interface 1 must have an endpoint\n", __func__); + r = -ENODEV; + goto fail2; + } ar2->ep[1] = &alt->endpoint[0].desc; r = ati_remote2_urb_init(ar2); if (r) - goto fail2; + goto fail3; ar2->channel_mask = channel_mask; ar2->mode_mask = mode_mask; r = ati_remote2_setup(ar2, ar2->channel_mask); if (r) - goto fail2; + goto fail3; usb_make_path(udev, ar2->phys, sizeof(ar2->phys)); strlcat(ar2->phys, "/input0", sizeof(ar2->phys)); @@ -842,11 +865,11 @@ static int ati_remote2_probe(struct usb_ r = sysfs_create_group(&udev->dev.kobj, &ati_remote2_attr_group); if (r) - goto fail2; + goto fail3; r = ati_remote2_input_init(ar2); if (r) - goto fail3; + goto fail4; usb_set_intfdata(interface, ar2); @@ -854,10 +877,11 @@ static int ati_remote2_probe(struct usb_ return 0; - fail3: + fail4: sysfs_remove_group(&udev->dev.kobj, &ati_remote2_attr_group); - fail2: + fail3: ati_remote2_urb_cleanup(ar2); + fail2: usb_driver_release_interface(&ati_remote2_driver, ar2->intf[1]); fail1: kfree(ar2);