From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41811 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751939AbcFRRCy (ORCPT ); Sat, 18 Jun 2016 13:02:54 -0400 Subject: Patch "ecryptfs: forbid opening files without mmap handler" has been added to the 4.6-stable tree To: jannh@google.com, gregkh@linuxfoundation.org, torvalds@linux-foundation.org, tyhicks@canonical.com Cc: , From: Date: Sat, 18 Jun 2016 10:02:53 -0700 Message-ID: <14662693735912@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ecryptfs: forbid opening files without mmap handler to the 4.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ecryptfs-forbid-opening-files-without-mmap-handler.patch and it can be found in the queue-4.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 2f36db71009304b3f0b95afacd8eba1f9f046b87 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Wed, 1 Jun 2016 11:55:06 +0200 Subject: ecryptfs: forbid opening files without mmap handler From: Jann Horn commit 2f36db71009304b3f0b95afacd8eba1f9f046b87 upstream. This prevents users from triggering a stack overflow through a recursive invocation of pagefault handling that involves mapping procfs files into virtual memory. Signed-off-by: Jann Horn Acked-by: Tyler Hicks Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ecryptfs/kthread.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/fs/ecryptfs/kthread.c +++ b/fs/ecryptfs/kthread.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "ecryptfs_kernel.h" struct ecryptfs_open_req { @@ -147,7 +148,7 @@ int ecryptfs_privileged_open(struct file flags |= IS_RDONLY(d_inode(lower_dentry)) ? O_RDONLY : O_RDWR; (*lower_file) = dentry_open(&req.path, flags, cred); if (!IS_ERR(*lower_file)) - goto out; + goto have_file; if ((flags & O_ACCMODE) == O_RDONLY) { rc = PTR_ERR((*lower_file)); goto out; @@ -165,8 +166,16 @@ int ecryptfs_privileged_open(struct file mutex_unlock(&ecryptfs_kthread_ctl.mux); wake_up(&ecryptfs_kthread_ctl.wait); wait_for_completion(&req.done); - if (IS_ERR(*lower_file)) + if (IS_ERR(*lower_file)) { rc = PTR_ERR(*lower_file); + goto out; + } +have_file: + if ((*lower_file)->f_op->mmap == NULL) { + fput(*lower_file); + *lower_file = NULL; + rc = -EMEDIUMTYPE; + } out: return rc; } Patches currently in stable-queue which might be from jannh@google.com are queue-4.6/ecryptfs-forbid-opening-files-without-mmap-handler.patch queue-4.6/sched-panic-on-corrupted-stack-end.patch queue-4.6/proc-prevent-stacking-filesystems-on-top.patch