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=-10.0 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 77C69C2BB84 for ; Fri, 4 Sep 2020 13:56:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3AD5D2065E for ; Fri, 4 Sep 2020 13:56:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599227819; bh=/VULTuInfm03Lezg/PEGNksKVEUO/TpaINRmGbUsIR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PYXzcijDt6QyClumIpWOCBB2R/QfiwYwNONElJ9+YuI8gJ9Rn47OpgV+QhmuUaEJS pvgj2MO/Qq75ih08HDvJD9T1wxWsW2lGCEBYXQ5zfFKa2uV+iPOGdzSMyr/vHCGjqV Zna6yr8aJCAaqJrQemJJ/0qCcUlmvsLtsW6M43mQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730544AbgIDN4y (ORCPT ); Fri, 4 Sep 2020 09:56:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:50880 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730637AbgIDNz2 (ORCPT ); Fri, 4 Sep 2020 09:55:28 -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 1F1802087C; Fri, 4 Sep 2020 13:30:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599226215; bh=/VULTuInfm03Lezg/PEGNksKVEUO/TpaINRmGbUsIR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L28EoxgDtavnfni9RvJGeGXmxtAfS6cpSoC/dNfy2aRq/JqcAJDOT5rWL+pxu1cxl dgF4jaqrMdL4DuQ1Kr5Ylj5BMLKtTVy8fBxQ4skp0Fqkx5JHWfDFkX11ZIdwvFO/Xw iAZRdssVzTrTmlk76tVmjS1ovQX2ZHKlbJe1lTIc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Zyngier , Benjamin Tissoires Subject: [PATCH 5.4 01/16] HID: core: Correctly handle ReportSize being zero Date: Fri, 4 Sep 2020 15:29:54 +0200 Message-Id: <20200904120257.278829676@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200904120257.203708503@linuxfoundation.org> References: <20200904120257.203708503@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 @@ -1598,6 +1598,17 @@ 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. */ @@ -1609,7 +1620,7 @@ 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); } @@ -1739,7 +1750,7 @@ 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;