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 7A3BEC11F8A for ; Mon, 12 Jul 2021 08:15:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F61D61420 for ; Mon, 12 Jul 2021 08:15:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357441AbhGLIRR (ORCPT ); Mon, 12 Jul 2021 04:17:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:56094 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245159AbhGLHdZ (ORCPT ); Mon, 12 Jul 2021 03:33:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C4B4A61374; Mon, 12 Jul 2021 07:30:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626075037; bh=mN06SF4VSjSXGXyu6dP0YwqQ3pJaEq3g/1y+qp+mK4E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uDrvLwRPF9fV55l8ONcRk9pcsbISsKXJIBbdLyXm1Eht1lcr8yaG5U4+iutB2+LPk QrpmuD5gNVNEjzRI+TIQK202RsX67ZwZeFVAUFd3QVVsa9dbrnGa7QFQP/etelwm72 oq4Ri22qpQGjrZmZZ4gy6t2/DKucg8aLAbKGF6e8= 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 5.13 040/800] Input: joydev - prevent use of not validated data in JSIOCSBTNMAP ioctl Date: Mon, 12 Jul 2021 08:01:03 +0200 Message-Id: <20210712060918.969960895@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060912.995381202@linuxfoundation.org> References: <20210712060912.995381202@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);