From 3283aeeace5e8965bf8d0338b278b5a2c818d743 Mon Sep 17 00:00:00 2001
From: Jeff Mahoney <jeffm@suse.com>
Date: Tue, 5 Jul 2016 17:32:29 -0400
Subject: [PATCH] Revert "ecryptfs: forbid opening files without mmap handler"
This reverts commit 2f36db71009304b3f0b95afacd8eba1f9f046b87.
It fixed a local root exploit but also introduced a dependency on
the lower file system implementing an mmap operation just to open a file,
which is a bit of a heavy hammer. The right fix is to have mmap depend
on the existence of the mmap handler instead.
Change-Id: I78753c9cadef7b43cd277d4827a096b45697c288
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
Git-commit: 78c4e172412de5d0456dc00d2b34050aa0b683b5
Signed-off-by: Dennis Cagle <d-cagle@codeaurora.org>
---
fs/ecryptfs/kthread.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c
index e818f5ac7a26..866bb18efefe 100644
--- a/fs/ecryptfs/kthread.c
+++ b/fs/ecryptfs/kthread.c
@@ -25,7 +25,6 @@
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/mount.h>
-#include <linux/file.h>
#include "ecryptfs_kernel.h"
struct ecryptfs_open_req {
@@ -148,7 +147,7 @@ int ecryptfs_privileged_open(struct file **lower_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 have_file;
+ goto out;
if ((flags & O_ACCMODE) == O_RDONLY) {
rc = PTR_ERR((*lower_file));
goto out;
@@ -166,16 +165,8 @@ int ecryptfs_privileged_open(struct file **lower_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;
}