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=-19.4 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, 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 914C3C07E99 for ; Mon, 12 Jul 2021 07:23:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 79457613FC for ; Mon, 12 Jul 2021 07:23:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239720AbhGLHZo (ORCPT ); Mon, 12 Jul 2021 03:25:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:33600 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240507AbhGLG6u (ORCPT ); Mon, 12 Jul 2021 02:58:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 56BFF613E8; Mon, 12 Jul 2021 06:56:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626072962; bh=mN06SF4VSjSXGXyu6dP0YwqQ3pJaEq3g/1y+qp+mK4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KEs3X2oiJ5YdnP+J+21A+N7QmxJ3XScbzCwPjVTzlU/y/tC/kY0JfBObsqoVshga9 WHh9GOActKILvCVZXA9g1opAJdH4l/qBMjQseqmtLZGcdL2WiF1TxoRs0RvP8jLMaG lBrONd2o2WNA5hs/EFUxrOGmkA+CjuD2pAuMIsj4= 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 5.12 037/700] Input: joydev - prevent use of not validated data in JSIOCSBTNMAP ioctl Date: Mon, 12 Jul 2021 08:02:00 +0200 Message-Id: <20210712060929.863410542@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -499,7 +499,7 @@ 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);