From owner-svn-src-head@freebsd.org  Wed Aug 10 13:50:22 2016
Return-Path: <owner-svn-src-head@freebsd.org>
Delivered-To: svn-src-head@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4E7DBBB46CF;
 Wed, 10 Aug 2016 13:50:22 +0000 (UTC) (envelope-from kib@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 1F3161B05;
 Wed, 10 Aug 2016 13:50:22 +0000 (UTC) (envelope-from kib@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u7ADoLxg076511;
 Wed, 10 Aug 2016 13:50:21 GMT (envelope-from kib@FreeBSD.org)
Received: (from kib@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id u7ADoLlA076510;
 Wed, 10 Aug 2016 13:50:21 GMT (envelope-from kib@FreeBSD.org)
Message-Id: <201608101350.u7ADoLlA076510@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org
 using -f
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Wed, 10 Aug 2016 13:50:21 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r303916 - head/sys/fs/tmpfs
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head/>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 10 Aug 2016 13:50:22 -0000

Author: kib
Date: Wed Aug 10 13:50:21 2016
New Revision: 303916
URL: https://svnweb.freebsd.org/changeset/base/303916

Log:
  Convert another tmpfs assert into runtime check.
  
  The offset of the directory file, passed to getdirentries(2) syscall,
  is user-controllable.  The value of the offset must not be asserted,
  instead the invalid value should be checked and rejected if invalid.
  
  Reported and tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/fs/tmpfs/tmpfs_subr.c

Modified: head/sys/fs/tmpfs/tmpfs_subr.c
==============================================================================
--- head/sys/fs/tmpfs/tmpfs_subr.c	Wed Aug 10 13:49:17 2016	(r303915)
+++ head/sys/fs/tmpfs/tmpfs_subr.c	Wed Aug 10 13:50:21 2016	(r303916)
@@ -819,10 +819,13 @@ tmpfs_dir_lookup_cookie(struct tmpfs_nod
 		goto out;
 	}
 
-	MPASS((cookie & TMPFS_DIRCOOKIE_MASK) == cookie);
-	dekey.td_hash = cookie;
-	/* Recover if direntry for cookie was removed */
-	de = RB_NFIND(tmpfs_dir, dirhead, &dekey);
+	if ((cookie & TMPFS_DIRCOOKIE_MASK) != cookie) {
+		de = NULL;
+	} else {
+		dekey.td_hash = cookie;
+		/* Recover if direntry for cookie was removed */
+		de = RB_NFIND(tmpfs_dir, dirhead, &dekey);
+	}
 	dc->tdc_tree = de;
 	dc->tdc_current = de;
 	if (de != NULL && tmpfs_dirent_duphead(de)) {