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 A109BC43461 for ; Tue, 8 Sep 2020 18:40:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 658CA2080C for ; Tue, 8 Sep 2020 18:40:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599590450; bh=HIels2xaM95JxAYzkcpSe0vmR3lhNMI/XaUw8mYvcQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Y4KBAAMusKku+q6fsahifGMqpNICUfOk/03vw/GJs5WDV0DQ4axX0DmO7EU1Nf0VZ H7rjR2nHuqRmWySeLeoRjghAx+iPdiDwGtI8THAwOvy9WlvxTQmghUN080FcBUwbdp kF7iaGVNQksOR1B17jhLtbyy+dfzoLKbiTDiflbg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731968AbgIHSkt (ORCPT ); Tue, 8 Sep 2020 14:40:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:52176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731211AbgIHQIC (ORCPT ); Tue, 8 Sep 2020 12:08:02 -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 E8DE523ECF; Tue, 8 Sep 2020 15:47:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599580050; bh=HIels2xaM95JxAYzkcpSe0vmR3lhNMI/XaUw8mYvcQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BR2kI9up5OadJTQMnCiqhjV5p9ZTCVtwB8FKzCQnRjqPCCPSrX7gklsIrUHmccjfL BII3jzVC9gbj4BEXLYUVWBFHDZt2+59WivJ/dRdcR1F+YiVoeyHWhvP9PN3m5NTGyw XXVdTPGMWM/FvXU4smmKdP1BZae6n9RLZISC1E48= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Benjamin Tissoires Subject: [PATCH 4.19 02/88] HID: core: Sanitize event code and type when mapping input Date: Tue, 8 Sep 2020 17:25:03 +0200 Message-Id: <20200908152221.209662874@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152221.082184905@linuxfoundation.org> References: <20200908152221.082184905@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 @@ -1125,6 +1125,10 @@ 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 @@ -841,6 +841,8 @@ static int mt_touch_input_mapping(struct code = BTN_0 + ((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 @@ -956,34 +956,49 @@ 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; } /** @@ -997,7 +1012,8 @@ 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); } /**