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=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 5B043C43461 for ; Fri, 11 Sep 2020 17:36:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B80B221E7 for ; Fri, 11 Sep 2020 17:36:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599845798; bh=3TUk0QMmGSrbMIZSTi77zDVjfJg52osVKczki7C3fyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BF7lo4CPlBiQ+KDd7a7gyqfkn2NZf61XPUtXOgVrEKwCGv8jXqS21N1KZEMy8sgVV aF6bZWOx/ZiPJL6aJ+xbYPdbpoUq+jfNHKphn1Yd82JIl9IELgzonKF1GH1DXzO04V oQJX+xDorf7Ml8t7RxfBonrlV7XXrNu9G6IDKuK4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726484AbgIKRgf (ORCPT ); Fri, 11 Sep 2020 13:36:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:48326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbgIKMxc (ORCPT ); Fri, 11 Sep 2020 08:53:32 -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 0BB9620758; Fri, 11 Sep 2020 12:53:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599828793; bh=3TUk0QMmGSrbMIZSTi77zDVjfJg52osVKczki7C3fyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pl6Q6ZDxPAg6RyTKOYfJm9FJUs0Vn3EyHU6+B/EyR4xJd6ktw25co+plSIVapsjkC FXmQ2cBAEuFKdIXJZaKKm2ZSZjj61fFSPAFJS9K3qmCZBC9uIE5AwNuWJ2e0FogFxL OZu1cgJ9DI2+2ExRVb3fJ2vLIJ/SNwoeft0Wwuso= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Benjamin Tissoires Subject: [PATCH 4.4 01/62] HID: core: Correctly handle ReportSize being zero Date: Fri, 11 Sep 2020 14:45:44 +0200 Message-Id: <20200911122502.469937711@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200911122502.395450276@linuxfoundation.org> References: <20200911122502.395450276@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 @@ -1368,6 +1368,17 @@ 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. */ @@ -1379,7 +1390,7 @@ 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); } @@ -1506,7 +1517,7 @@ 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;