From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754708AbcHUQGx (ORCPT ); Sun, 21 Aug 2016 12:06:53 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:55468 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932274AbcHUPcz (ORCPT ); Sun, 21 Aug 2016 11:32:55 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jeff Mahoney , Tyler Hicks , Greg Kroah-Hartman , Willy Tarreau Subject: [PATCH 3.10 144/180] ecryptfs: don't allow mmap when the lower fs doesn't support it Date: Sun, 21 Aug 2016 17:31:14 +0200 Message-Id: <1471793510-13022-145-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1471793510-13022-1-git-send-email-w@1wt.eu> References: <1471793510-13022-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jeff Mahoney commit f0fe970df3838c202ef6c07a4c2b36838ef0a88b upstream. There are legitimate reasons to disallow mmap on certain files, notably in sysfs or procfs. We shouldn't emulate mmap support on file systems that don't offer support natively. CVE-2016-1583 Signed-off-by: Jeff Mahoney [tyhicks: clean up f_op check by using ecryptfs_file_to_lower()] Signed-off-by: Tyler Hicks Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- fs/ecryptfs/file.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 9ff3664..d4644cc 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -183,6 +183,19 @@ out: return rc; } +static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct file *lower_file = ecryptfs_file_to_lower(file); + /* + * Don't allow mmap on top of file systems that don't support it + * natively. If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs + * allows recursive mounting, this will need to be extended. + */ + if (!lower_file->f_op->mmap) + return -ENODEV; + return generic_file_mmap(file, vma); +} + /** * ecryptfs_open * @inode: inode speciying file to open @@ -358,7 +371,7 @@ const struct file_operations ecryptfs_main_fops = { #ifdef CONFIG_COMPAT .compat_ioctl = ecryptfs_compat_ioctl, #endif - .mmap = generic_file_mmap, + .mmap = ecryptfs_mmap, .open = ecryptfs_open, .flush = ecryptfs_flush, .release = ecryptfs_release, -- 2.8.0.rc2.1.gbe9624a