eCryptfs: Fix data corruption when using ecryptfs_passthrough

ecryptfs_passthrough is a mount option that allows eCryptfs to allow
data to be written to non-eCryptfs files in the lower filesystem.  The
passthrough option was causing data corruption due to it not always
being treated as a non-eCryptfs file.

The first 8 bytes of an eCryptfs file contains the decrypted file size.
This value was being written to the non-eCryptfs files, too.  Also,
extra 0x00 characters were being written to make the file size a
multiple of PAGE_CACHE_SIZE.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

1 files changed, 2 insertions, 19 deletions

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 8b65f289ee00..b91851f1cda3 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -483,15 +483,7 @@ int ecryptfs_encrypt_page(struct page *page)
         ecryptfs_inode = page->mapping->host;
         crypt_stat =
                 &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
-        if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
-                rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page,
-                                                       0, PAGE_CACHE_SIZE);
-                if (rc)
-                        printk(KERN_ERR "%s: Error attempting to copy "
-                               "page at index [%ld]\n", __func__,
-                               page->index);
-                goto out;
-        }
+        BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
         enc_extent_page = alloc_page(GFP_USER);
         if (!enc_extent_page) {
                 rc = -ENOMEM;
@@ -620,16 +612,7 @@ int ecryptfs_decrypt_page(struct page *page)
         ecryptfs_inode = page->mapping->host;
         crypt_stat =
                 &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
-        if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
-                rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
-                                                      PAGE_CACHE_SIZE,
-                                                      ecryptfs_inode);
-                if (rc)
-                        printk(KERN_ERR "%s: Error attempting to copy "
-                               "page at index [%ld]\n", __func__,
-                               page->index);
-                goto out;
-        }
+        BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
         enc_extent_page = alloc_page(GFP_USER);
         if (!enc_extent_page) {
                 rc = -ENOMEM;