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=-10.0 required=3.0 tests=BAYES_00,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=ham 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 092AFC433DF for ; Mon, 3 Aug 2020 12:23:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1AF5204EC for ; Mon, 3 Aug 2020 12:23:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596457429; bh=Rxo3c6npIb6NdgDIk6bWOZC5ouNHLAYGjf7Cf5eDtmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pqZfQVqpNgV1Ge68Nr2gIRUHoI1hRcrVihs+HHVEBOFoiqVxbSwqyeEgmAwTe3Ciw fRAGSt+E3DVU5v527WLNP7jjoQ6vLrF7thoj3+ILmy9cZgsNRzqIriBV2rr4ccn4AX bMq5VykLDH1pEx7CcOBiZwdC+CZCKeD3WzFOOoJM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727932AbgHCMXt (ORCPT ); Mon, 3 Aug 2020 08:23:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:47966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727919AbgHCMXr (ORCPT ); Mon, 3 Aug 2020 08:23:47 -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 6F769204EC; Mon, 3 Aug 2020 12:23:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596457426; bh=Rxo3c6npIb6NdgDIk6bWOZC5ouNHLAYGjf7Cf5eDtmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sDh6nTs7QWzTxbNjiUzcXQmtmMxU842O3h1UuOajvmwNeMpJnq65NH3L9zH/ctY+c 3Pn9J2CEMvpUDoVeBiytFrLXz4RmhAOdqEaWTu5ir+PjOldUq7XEA7zWQMJctsoweo tZTvBePK89MbuqC2sS9h1ElWZ00BGP1n7rw21hQo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Peilin Ye , Santosh Shilimkar , "David S. Miller" Subject: [PATCH 5.7 032/120] rds: Prevent kernel-infoleak in rds_notify_queue_get() Date: Mon, 3 Aug 2020 14:18:10 +0200 Message-Id: <20200803121904.391315797@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200803121902.860751811@linuxfoundation.org> References: <20200803121902.860751811@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: Peilin Ye commit bbc8a99e952226c585ac17477a85ef1194501762 upstream. rds_notify_queue_get() is potentially copying uninitialized kernel stack memory to userspace since the compiler may leave a 4-byte hole at the end of `cmsg`. In 2016 we tried to fix this issue by doing `= { 0 };` on `cmsg`, which unfortunately does not always initialize that 4-byte hole. Fix it by using memset() instead. Cc: stable@vger.kernel.org Fixes: f037590fff30 ("rds: fix a leak of kernel memory") Fixes: bdbe6fbc6a2f ("RDS: recv.c") Suggested-by: Dan Carpenter Signed-off-by: Peilin Ye Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rds/recv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/rds/recv.c +++ b/net/rds/recv.c @@ -450,12 +450,13 @@ static int rds_still_queued(struct rds_s int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr) { struct rds_notifier *notifier; - struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */ + struct rds_rdma_notify cmsg; unsigned int count = 0, max_messages = ~0U; unsigned long flags; LIST_HEAD(copy); int err = 0; + memset(&cmsg, 0, sizeof(cmsg)); /* fill holes with zero */ /* put_cmsg copies to user space and thus may sleep. We can't do this * with rs_lock held, so first grab as many notifications as we can stuff