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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 0721CC5B57D for ; Tue, 2 Jul 2019 08:04:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C925121848 for ; Tue, 2 Jul 2019 08:04:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562054651; bh=+5wh1TPC8500DTvsHtSfTy6J2D318x38RgUyQSLTuhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KlgnBLO/5HIVVBDFTNAsD/OW1GHfNCsB/yN5inubRF0XCkJ6ipPtrqLdtvBOKZ8MO 1R8rvfxAcS+ahmw3y5qj+QQ9msFBmxmuIRBwwvd9vb7qNiVKMO81nhJM9mNJRL2rDT 96w/wctTWFP656k4oBOeE68F1iy7j7+pni72qOGM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbfGBIEK (ORCPT ); Tue, 2 Jul 2019 04:04:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:49468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727584AbfGBIEH (ORCPT ); Tue, 2 Jul 2019 04:04:07 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 160CE21841; Tue, 2 Jul 2019 08:04:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562054646; bh=+5wh1TPC8500DTvsHtSfTy6J2D318x38RgUyQSLTuhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CXBdD0BNhCf7/GwvrYGJe9qwhgq8pIZnTMGUILy4cFcd+saBdA2fAQwrbg9vrwz5d 0Ll6v4wAlRklY1GZHVSUJX942BLSnVURNj737bCDlWvlD+LwjczDYToFk4ZPKakPWi PJ4G4dfRnaK289+MM9Ym37Wzj5JphtAmAQcHqmK0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, JingYi Hou , "David S. Miller" Subject: [PATCH 5.1 34/55] net: remove duplicate fetch in sock_getsockopt Date: Tue, 2 Jul 2019 10:01:42 +0200 Message-Id: <20190702080125.896132945@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190702080124.103022729@linuxfoundation.org> References: <20190702080124.103022729@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: JingYi Hou [ Upstream commit d0bae4a0e3d8c5690a885204d7eb2341a5b4884d ] In sock_getsockopt(), 'optlen' is fetched the first time from userspace. 'len < 0' is then checked. Then in condition 'SO_MEMINFO', 'optlen' is fetched the second time from userspace. If change it between two fetches may cause security problems or unexpected behaivor, and there is no reason to fetch it a second time. To fix this, we need to remove the second fetch. Signed-off-by: JingYi Hou Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/sock.c | 3 --- 1 file changed, 3 deletions(-) --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1482,9 +1482,6 @@ int sock_getsockopt(struct socket *sock, { u32 meminfo[SK_MEMINFO_VARS]; - if (get_user(len, optlen)) - return -EFAULT; - sk_get_meminfo(sk, meminfo); len = min_t(unsigned int, len, sizeof(meminfo));