1 files changed, 7 insertions, 0 deletions

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 24749bf0668f..f0be29051528 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -192,6 +192,13 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
                                       | ECRYPTFS_ENCRYPTED);
         }
         mutex_unlock(&crypt_stat->cs_mutex);
+        if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY)
+            && !(file->f_flags & O_RDONLY)) {
+                rc = -EPERM;
+                printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs "
+                       "file must hence be opened RO\n", __func__);
+                goto out;
+        }
         ecryptfs_set_file_lower(
                 file, ecryptfs_inode_to_private(inode)->lower_file);
         if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {