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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CC95C4332F for ; Mon, 12 Dec 2022 13:52:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232797AbiLLNwH (ORCPT ); Mon, 12 Dec 2022 08:52:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233034AbiLLNv3 (ORCPT ); Mon, 12 Dec 2022 08:51:29 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E41B8140E0 for ; Mon, 12 Dec 2022 05:50:46 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9960AB80B78 for ; Mon, 12 Dec 2022 13:50:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E42ECC433D2; Mon, 12 Dec 2022 13:50:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670853044; bh=55LRY2CZ6QAmnSz7+2cnqjbDvw0PzXkBfwFtJwW8dqw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L8MtzYm2SKzxbmgXEeHN7HeorGUJgn/YqDg2Ig8TYz6kgguZV/uLGGI3SlW40dc8n j5UohZOvhVVdaVGXYaRLRxu4jyQS5vI9JvbqLvTebu+UP2BFQW0MTi8aPct07b9rN/ n5lKEASu76b+mQ5nbiNogOTKLV7Idwl8T2Jvf4tE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Anastasia Belova , Jiri Kosina Subject: [PATCH 4.19 20/49] HID: hid-lg4ff: Add check for empty lbuf Date: Mon, 12 Dec 2022 14:18:58 +0100 Message-Id: <20221212130914.701449554@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221212130913.666185567@linuxfoundation.org> References: <20221212130913.666185567@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anastasia Belova commit d180b6496143cd360c5d5f58ae4b9a8229c1f344 upstream. If an empty buf is received, lbuf is also empty. So lbuf is accessed by index -1. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: f31a2de3fe36 ("HID: hid-lg4ff: Allow switching of Logitech gaming wheels between compatibility modes") Signed-off-by: Anastasia Belova Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-lg4ff.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/hid/hid-lg4ff.c +++ b/drivers/hid/hid-lg4ff.c @@ -878,6 +878,12 @@ static ssize_t lg4ff_alternate_modes_sto return -ENOMEM; i = strlen(lbuf); + + if (i == 0) { + kfree(lbuf); + return -EINVAL; + } + if (lbuf[i-1] == '\n') { if (i == 1) { kfree(lbuf);