4.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jeff Mahoney <jeffm@xxxxxxxx>
commit 78c4e172412de5d0456dc00d2b34050aa0b683b5 upstream.
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.
Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ecryptfs/kthread.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
--- 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
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
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;
}
--
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