From owner-svn-src-all@FreeBSD.ORG  Thu Nov 22 16:20:09 2012
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id 7302277F;
 Thu, 22 Nov 2012 16:20:09 +0000 (UTC) (envelope-from kib@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 by mx1.freebsd.org (Postfix) with ESMTP id 58ACC8FC18;
 Thu, 22 Nov 2012 16:20:09 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
 by svn.freebsd.org (8.14.5/8.14.5) with ESMTP id qAMGK9Hj018867;
 Thu, 22 Nov 2012 16:20:09 GMT (envelope-from kib@svn.freebsd.org)
Received: (from kib@localhost)
 by svn.freebsd.org (8.14.5/8.14.5/Submit) id qAMGK9wW018866;
 Thu, 22 Nov 2012 16:20:09 GMT (envelope-from kib@svn.freebsd.org)
Message-Id: <201211221620.qAMGK9wW018866@svn.freebsd.org>
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Thu, 22 Nov 2012 16:20:09 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org
Subject: svn commit: r243408 - stable/9/sys/dev/md
X-SVN-Group: stable-9
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 22 Nov 2012 16:20:09 -0000

Author: kib
Date: Thu Nov 22 16:20:08 2012
New Revision: 243408
URL: http://svnweb.freebsd.org/changeset/base/243408

Log:
  MFC r242744:
  Zero the newly allocated md(4) swap-backed page to prevent random
  kernel memory leakage to userspace.

Modified:
  stable/9/sys/dev/md/md.c
Directory Properties:
  stable/9/sys/   (props changed)
  stable/9/sys/dev/   (props changed)

Modified: stable/9/sys/dev/md/md.c
==============================================================================
--- stable/9/sys/dev/md/md.c	Thu Nov 22 16:14:41 2012	(r243407)
+++ stable/9/sys/dev/md/md.c	Thu Nov 22 16:20:08 2012	(r243408)
@@ -677,6 +677,15 @@ mdstart_swap(struct md_s *sc, struct bio
 				sched_unpin();
 				vm_page_wakeup(m);
 				break;
+			} else if (rv == VM_PAGER_FAIL) {
+				/*
+				 * Pager does not have the page.  Zero
+				 * the allocated page, and mark it as
+				 * valid. Do not set dirty, the page
+				 * can be recreated if thrown out.
+				 */
+				bzero((void *)sf_buf_kva(sf), PAGE_SIZE);
+				m->valid = VM_PAGE_BITS_ALL;
 			}
 			bcopy((void *)(sf_buf_kva(sf) + offs), p, len);
 			cpu_flush_dcache(p, len);