From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE0D7C433E2 for ; Fri, 11 Sep 2020 17:23:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97DC9221E7 for ; Fri, 11 Sep 2020 17:23:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599844988; bh=a4XW114z+HKfFa0PWhRmUfltqQ7/Le9Ecxk0vMQmFt0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=W4Ioo+nevgHdlhUFjpehacHvIJBU8gcrOcI1FrNkJ5G8E0iKCBJlF1WLBoZNqcV0k FC9rLRbim4mz93nAb+xkxNllqcnnXIsu5KQ0yxRJpGgMHBa0i4Bw1TM0btCcMmownw og9YGFgjFWbEsZLp+3KnBie459Kysi3vOY9M7TFU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726419AbgIKRWw (ORCPT ); Fri, 11 Sep 2020 13:22:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:52804 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbgIKNAL (ORCPT ); Fri, 11 Sep 2020 09:00:11 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 07C852226A; Fri, 11 Sep 2020 12:56:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599828981; bh=a4XW114z+HKfFa0PWhRmUfltqQ7/Le9Ecxk0vMQmFt0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pgeODwtUTEUFY+oaRrb+US3cE98lK3EtfXOum9bDlQ5uXT7iDDZee9gBktkrzms7G epVgBV7i/Y144DCBzFjUTertvf3iU1271eM+arhwF576yTi2pgz6v/sK2o8U1E1KU4 YwwkD8/I9zpz3DX0y7/l1TXg5vzNyaP7NIW5IdNA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Benjamin Tissoires Subject: [PATCH 4.9 02/71] HID: core: Sanitize event code and type when mapping input Date: Fri, 11 Sep 2020 14:45:46 +0200 Message-Id: <20200911122505.058850881@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200911122504.928931589@linuxfoundation.org> References: <20200911122504.928931589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marc Zyngier commit 35556bed836f8dc07ac55f69c8d17dce3e7f0e25 upstream. When calling into hid_map_usage(), the passed event code is blindly stored as is, even if it doesn't fit in the associated bitmap. This event code can come from a variety of sources, including devices masquerading as input devices, only a bit more "programmable". Instead of taking the event code at face value, check that it actually fits the corresponding bitmap, and if it doesn't: - spit out a warning so that we know which device is acting up - NULLify the bitmap pointer so that we catch unexpected uses Code paths that can make use of untrusted inputs can now check that the mapping was indeed correct and bail out if not. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-input.c | 4 ++++ drivers/hid/hid-multitouch.c | 2 ++ include/linux/hid.h | 42 +++++++++++++++++++++++++++++------------- 3 files changed, 35 insertions(+), 13 deletions(-) --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1026,6 +1026,10 @@ static void hidinput_configure_usage(str } mapped: + /* Mapping failed, bail out */ + if (!bit) + return; + if (device->driver->input_mapped && device->driver->input_mapped(device, hidinput, field, usage, &bit, &max) < 0) { --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -567,6 +567,8 @@ static int mt_touch_input_mapping(struct case HID_UP_BUTTON: code = BTN_MOUSE + ((usage->hid - 1) & HID_USAGE); hid_map_usage(hi, usage, bit, max, EV_KEY, code); + if (!*bit) + return -1; input_set_capability(hi->input, EV_KEY, code); return 1; --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -874,34 +874,49 @@ static inline void hid_device_io_stop(st * @max: maximal valid usage->code to consider later (out parameter) * @type: input event type (EV_KEY, EV_REL, ...) * @c: code which corresponds to this usage and type + * + * The value pointed to by @bit will be set to NULL if either @type is + * an unhandled event type, or if @c is out of range for @type. This + * can be used as an error condition. */ static inline void hid_map_usage(struct hid_input *hidinput, struct hid_usage *usage, unsigned long **bit, int *max, - __u8 type, __u16 c) + __u8 type, unsigned int c) { struct input_dev *input = hidinput->input; - - usage->type = type; - usage->code = c; + unsigned long *bmap = NULL; + unsigned int limit = 0; switch (type) { case EV_ABS: - *bit = input->absbit; - *max = ABS_MAX; + bmap = input->absbit; + limit = ABS_MAX; break; case EV_REL: - *bit = input->relbit; - *max = REL_MAX; + bmap = input->relbit; + limit = REL_MAX; break; case EV_KEY: - *bit = input->keybit; - *max = KEY_MAX; + bmap = input->keybit; + limit = KEY_MAX; break; case EV_LED: - *bit = input->ledbit; - *max = LED_MAX; + bmap = input->ledbit; + limit = LED_MAX; break; } + + if (unlikely(c > limit || !bmap)) { + pr_warn_ratelimited("%s: Invalid code %d type %d\n", + input->name, c, type); + *bit = NULL; + return; + } + + usage->type = type; + usage->code = c; + *max = limit; + *bit = bmap; } /** @@ -915,7 +930,8 @@ static inline void hid_map_usage_clear(s __u8 type, __u16 c) { hid_map_usage(hidinput, usage, bit, max, type, c); - clear_bit(c, *bit); + if (*bit) + clear_bit(usage->code, *bit); } /**