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 <jannh@google.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/mount.h>
#include "ecryptfs_kernel.h"
struct ecryptfs_open_req {
#include "ecryptfs_kernel.h"
struct ecryptfs_open_req {
flags |= IS_RDONLY(d_inode(lower_dentry)) ? O_RDONLY : O_RDWR;
(*lower_file) = dentry_open(&req.path, flags, cred);
if (!IS_ERR(*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))
if ((flags & O_ACCMODE) == O_RDONLY) {
rc = PTR_ERR((*lower_file));
goto out;
if ((flags & O_ACCMODE) == O_RDONLY) {
rc = PTR_ERR((*lower_file));
goto out;
mutex_unlock(&ecryptfs_kthread_ctl.mux);
wake_up(&ecryptfs_kthread_ctl.wait);
wait_for_completion(&req.done);
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);
rc = PTR_ERR(*lower_file);
+ goto out;
+ }
+have_file:
+ if ((*lower_file)->f_op->mmap == NULL) {
+ fput(*lower_file);
+ *lower_file = NULL;
+ rc = -EMEDIUMTYPE;
+ }