1 files changed, 14 insertions, 1 deletions

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 53d0141b9c20..ca4e83750214 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -169,6 +169,19 @@ 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 specifying file to open
@@ -403,7 +416,7 @@ 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,