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 4752FC2D0E4 for ; Fri, 11 Sep 2020 17:36:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E937122205 for ; Fri, 11 Sep 2020 17:36:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599845776; bh=3TUk0QMmGSrbMIZSTi77zDVjfJg52osVKczki7C3fyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ixGZJPO13wYYIPLPccPotg7w8XkLxlA+Gb68tdmsVLRXZTCkRaEM1mArqOzh2NhrB NWCHXDAp1Qv4KkOSnVlJWuyMrPGcq0P4Vm60rAm3ziI6I2VzDYMsc2Q9RBqz82JLqs 9NcSREyJOBspiRNi/0AbxqiXT6uAWDZyWrfWjZhE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726173AbgIKRgO (ORCPT ); Fri, 11 Sep 2020 13:36:14 -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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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;