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,USER_AGENT_GIT autolearn=unavailable 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 549AEC433E2 for ; Tue, 8 Sep 2020 19:01:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1261C2087D for ; Tue, 8 Sep 2020 19:01:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599591667; bh=jRAfFpWjDzSiVLWJ/01vaQ66oeAPndpYE2EnvInALxo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NF43H/NqSQBOoFb2ODEeQBTMwU65jIRzHW7V1T9bNE9mL4fOB/fWvm0HNDOIkfajQ sgPFOutFP8QFENhr0tGmyLFgQE002X7+DdpOBhinTdBuSf9erNyEnAYVoYx0tyGtOM bzMtYaY2GZVHWvPgZT67obfMmFVUI/P5caqtqYZA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731456AbgIHTBD (ORCPT ); Tue, 8 Sep 2020 15:01:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:52180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731201AbgIHQIC (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 5191D23EB3; Tue, 8 Sep 2020 15:47:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599580045; bh=jRAfFpWjDzSiVLWJ/01vaQ66oeAPndpYE2EnvInALxo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cOMu+pkZxzwDQB5jvHCNFRJCkK7BNLtyErS9bgS3jjRs8XNrUE+y2gBnOoeD5UNGZ nVuEvFRvbQp1vp7w0LYQJKCqUGpucm40tnT5nBRatmbp0VuxXj6IYhIfJuCnm6jABs 3F8BFYsirB2QWVeLWgreAN3GNB8VWMDqCfttlIuM= 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 01/88] HID: core: Correctly handle ReportSize being zero Date: Tue, 8 Sep 2020 17:25:02 +0200 Message-Id: <20200908152221.161126100@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 X-stable: review X-Patchwork-Hint: ignore 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 bce1305c0ece3dc549663605e567655dd701752c upstream. It appears that a ReportSize value of zero is legal, even if a bit non-sensical. Most of the HID code seems to handle that gracefully, except when computing the total size in bytes. When fed as input to memset, this leads to some funky outcomes. Detect the corner case and correctly compute the size. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1426,6 +1426,17 @@ static void hid_output_field(const struc } /* + * Compute the size of a report. + */ +static size_t hid_compute_report_size(struct hid_report *report) +{ + if (report->size) + return ((report->size - 1) >> 3) + 1; + + return 0; +} + +/* * Create a report. 'data' has to be allocated using * hid_alloc_report_buf() so that it has proper size. */ @@ -1437,7 +1448,7 @@ void hid_output_report(struct hid_report if (report->id > 0) *data++ = report->id; - memset(data, 0, ((report->size - 1) >> 3) + 1); + memset(data, 0, hid_compute_report_size(report)); for (n = 0; n < report->maxfield; n++) hid_output_field(report->device, report->field[n], data); } @@ -1564,7 +1575,7 @@ int hid_report_raw_event(struct hid_devi csize--; } - rsize = ((report->size - 1) >> 3) + 1; + rsize = hid_compute_report_size(report); if (report_enum->numbered && rsize >= HID_MAX_BUFFER_SIZE) rsize = HID_MAX_BUFFER_SIZE - 1;