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=-9.8 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 974D9C433DF for ; Thu, 20 Aug 2020 12:17:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D8C220855 for ; Thu, 20 Aug 2020 12:17:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597925867; bh=uP7qBUfQho+By8w77QxSTaXPo2Q+DtMc5/PUP08XXWg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TBfV+By00/PYjhrZLFL5Kd4TBKwPG9KbNwq1dZUT1A8/9apQqmoOo+UChyS4DrGUt loytRwJG99TDzazlWueEsM7rvhEko8aKZbeQwkcX6P10lQ1rWn84UE25RIZktFr+7N rqprTTvV5lQO9h4u4HsoBStMTE5LjieC1WKWDilM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730347AbgHTMQc (ORCPT ); Thu, 20 Aug 2020 08:16:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:40328 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730263AbgHTJ4s (ORCPT ); Thu, 20 Aug 2020 05:56:48 -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 1676F208DB; Thu, 20 Aug 2020 09:56:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917407; bh=uP7qBUfQho+By8w77QxSTaXPo2Q+DtMc5/PUP08XXWg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yJKipr4NcuqZEwpWsfaDA4fs3UczlRwSOLlhQcsd0p/eKkhVsveWcG0In+j5usUJT GKxeNM5YU7Vc0hVNvD45MXiBwA/5EwIMhSjGmj8l/cq4egfi62G70rc+ibbJlsa9o/ eWCLk4D2dv+4zVb4NnFB9C+ETYMTYLDQgja90OJg= 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 4.9 020/212] rds: Prevent kernel-infoleak in rds_notify_queue_get() Date: Thu, 20 Aug 2020 11:19:53 +0200 Message-Id: <20200820091603.352748362@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091602.251285210@linuxfoundation.org> References: <20200820091602.251285210@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 @@ -405,12 +405,13 @@ 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