From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1427278-1518185093-2-13330182005488965901 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES enda, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518185092; b=raGx+pdy5gj24AdOl1VSzlaxzPlmVDzioc5UVg55AqSCpvQ CMgkyoCPQ3efEILUI90l1ZxJ+1Nmnv7jFw341FS7FlH3cU28/C8HqU0e1jS8U8GO okduHx997ECg1j15CyO3tTE8zKHaAozHsMcA5rTI3wZDdGOeefzjOB1ajfgruha2 CXAFuMe1KKGGIC2OwAkSmq1bBPiqeAVEU1oQUiUspsQ0OIbS1XD0c4II5Ku6Tc1u C3c8cVWO2Vjt9aDUIHj3kJuWDGFOyAwMA7o0yfKT1+lhkaz2exK7byRhO8rUfqkZ s+kOFlOKfVTY614nShu7Q7umza+iCcPgdeyxRjA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1518185092; bh=ph60OCZ3mNiy1CjEvXcVax7T5/ iKIyAlhvE5FetkF3s=; b=SoRovpIXgszgvALXJ1Wbinox8TcVB0NGSd+1Xm4McM OILNX04uXBKPqOz9OM0mwAcDPd6KBpToJy0XQU6wygLnlVxhkhdC+23/xUPdsqfM 3GBrUtXcYp9J25TW+ELEEijFnzwUro5nN64CzZrswjErOQN/Kg4f0VZTpPPGO8pk wZhnhYEc6hEposR31zTrEfYuZYpdASjPKiFCPJZ4BbQtinPYFjsv1MOzA939bb02 kUm8ytGrTNnCgCk8ff5kQ/krBA9CAiS7IY94Ts+wctEq9fAKNojSH3pcpgTASoVO kBdsWzrTNq71RqgxilWZz9f1rQLCQiRM3t5gu6NS8MGQ== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753229AbeBINne (ORCPT ); Fri, 9 Feb 2018 08:43:34 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:50836 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbeBINnd (ORCPT ); Fri, 9 Feb 2018 08:43:33 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Williams , Thomas Gleixner , linux-arch@vger.kernel.org, kernel-hardening@lists.openwall.com, Al Viro , torvalds@linux-foundation.org, alan@linux.intel.com, David Woodhouse Subject: [PATCH 4.9 65/92] vfs, fdtable: Prevent bounds-check bypass via speculative execution Date: Fri, 9 Feb 2018 14:39:34 +0100 Message-Id: <20180209133935.948520836@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180209133931.211869118@linuxfoundation.org> References: <20180209133931.211869118@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams (cherry picked from commit 56c30ba7b348b90484969054d561f711ba196507) 'fd' is a user controlled value that is used as a data dependency to read from the 'fdt->fd' array. In order to avoid potential leaks of kernel memory values, block speculative execution of the instruction stream that could issue reads based on an invalid 'file *' returned from __fcheck_files. Co-developed-by: Elena Reshetova Signed-off-by: Dan Williams Signed-off-by: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727418500.33451.17392199002892248656.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- include/linux/fdtable.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -81,8 +82,10 @@ static inline struct file *__fcheck_file { struct fdtable *fdt = rcu_dereference_raw(files->fdt); - if (fd < fdt->max_fds) + if (fd < fdt->max_fds) { + fd = array_index_nospec(fd, fdt->max_fds); return rcu_dereference_raw(fdt->fd[fd]); + } return NULL; }