From patchwork Mon Jul 19 14:49:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 481370 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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 11B35C07E9D for ; Mon, 19 Jul 2021 15:07:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F00E86113C for ; Mon, 19 Jul 2021 15:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243018AbhGSO0S (ORCPT ); Mon, 19 Jul 2021 10:26:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:36970 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244114AbhGSOYt (ORCPT ); Mon, 19 Jul 2021 10:24:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5612861205; Mon, 19 Jul 2021 15:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626707109; bh=+AwoeEsZVqWrlHWrUGR9wr/ZOhlF+XMSvDq5xSbqZoM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WLB+WhOGTQDQm2E+L5saAzGmCMVEp/NpIJymq+egMtQ4+8XgdgNhG53qc669yPQfU B8duQVY7ddjFuOlDXhm3uSX+93Z+GQSfCDvvBkGkvE5YI02Pv96SQ2Fo/7ItO9/iok NeBD361zkcRe/gZK3yNJBcTjB5yDXWPVRiG6HUw4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Murray McAllister , Linus Torvalds , Alexander Larkin , Dmitry Torokhov Subject: [PATCH 4.9 009/245] Input: joydev - prevent use of not validated data in JSIOCSBTNMAP ioctl Date: Mon, 19 Jul 2021 16:49:11 +0200 Message-Id: <20210719144940.688608262@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144940.288257948@linuxfoundation.org> References: <20210719144940.288257948@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Larkin commit f8f84af5da9ee04ef1d271528656dac42a090d00 upstream. Even though we validate user-provided inputs we then traverse past validated data when applying the new map. The issue was originally discovered by Murray McAllister with this simple POC (if the following is executed by an unprivileged user it will instantly panic the system): int main(void) { int fd, ret; unsigned int buffer[10000]; fd = open("/dev/input/js0", O_RDONLY); if (fd == -1) printf("Error opening file\n"); ret = ioctl(fd, JSIOCSBTNMAP & ~IOCSIZE_MASK, &buffer); printf("%d\n", ret); } The solution is to traverse internal buffer which is guaranteed to only contain valid date when constructing the map. Fixes: 182d679b2298 ("Input: joydev - prevent potential read overflow in ioctl") Fixes: 999b874f4aa3 ("Input: joydev - validate axis/button maps before clobbering current ones") Reported-by: Murray McAllister Suggested-by: Linus Torvalds Signed-off-by: Alexander Larkin Link: https://lore.kernel.org/r/20210620120030.1513655-1-avlarkin82@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/input/joydev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/input/joydev.c +++ b/drivers/input/joydev.c @@ -492,7 +492,7 @@ static int joydev_handle_JSIOCSBTNMAP(st memcpy(joydev->keypam, keypam, len); for (i = 0; i < joydev->nkey; i++) - joydev->keymap[keypam[i] - BTN_MISC] = i; + joydev->keymap[joydev->keypam[i] - BTN_MISC] = i; out: kfree(keypam);