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>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 55b3145..5ed86e2 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -814,6 +814,13 @@
size_t num_zeros = (PAGE_CACHE_SIZE
- (new_length & ~PAGE_CACHE_MASK));
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
+ rc = vmtruncate(inode, new_length);
+ if (rc)
+ goto out_free;
+ rc = vmtruncate(lower_dentry->d_inode, new_length);
+ goto out_free;
+ }
if (num_zeros) {
char *zeros_virt;
@@ -915,8 +922,6 @@
}
rc = 0;
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
- mutex_unlock(&crypt_stat->cs_mutex);
- goto out;
}
}
mutex_unlock(&crypt_stat->cs_mutex);