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=-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=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 2D009C636C9 for ; Mon, 19 Jul 2021 15:47:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 187F661364 for ; Mon, 19 Jul 2021 15:47:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344585AbhGSPGb (ORCPT ); Mon, 19 Jul 2021 11:06:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:41944 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344338AbhGSOsq (ORCPT ); Mon, 19 Jul 2021 10:48:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 90EC76140C; Mon, 19 Jul 2021 15:28:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626708491; bh=RXuGvN4EG/5/HGSDGhKuFi742Ltwhgn7me/a9zNM5/A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QF5sWStn2oA7g/Zv0Fp1iJNb5zWs0DJ49bm5vhpm6tVynt58Sn5aj4/DDm+nno6Ag NwEkKT7uoyfeweRT3Ra/C29nhW+yYndz72EzyFy2+6aRs+Z7XDgUHaeeDMX3nJuQ5u XKWDbbsqQRvCzqwtL/VTVsrc+GVk9CqRid9/cyLw= 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 4.19 014/421] Input: joydev - prevent use of not validated data in JSIOCSBTNMAP ioctl Date: Mon, 19 Jul 2021 16:47:05 +0200 Message-Id: <20210719144946.779558854@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@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 @@ -504,7 +504,7 @@ 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);