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/read_write.c b/fs/ecryptfs/read_write.c
index 75c2ea9..a137c6e 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -117,13 +117,15 @@
size_t size)
{
struct page *ecryptfs_page;
+ struct ecryptfs_crypt_stat *crypt_stat;
+ struct inode *ecryptfs_inode = ecryptfs_file->f_dentry->d_inode;
char *ecryptfs_page_virt;
- loff_t ecryptfs_file_size =
- i_size_read(ecryptfs_file->f_dentry->d_inode);
+ loff_t ecryptfs_file_size = i_size_read(ecryptfs_inode);
loff_t data_offset = 0;
loff_t pos;
int rc = 0;
+ crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
/*
* if we are writing beyond current size, then start pos
* at the current size - we'll fill in zeros from there.
@@ -184,7 +186,13 @@
flush_dcache_page(ecryptfs_page);
SetPageUptodate(ecryptfs_page);
unlock_page(ecryptfs_page);
- rc = ecryptfs_encrypt_page(ecryptfs_page);
+ if (crypt_stat->flags & ECRYPTFS_ENCRYPTED)
+ rc = ecryptfs_encrypt_page(ecryptfs_page);
+ else
+ rc = ecryptfs_write_lower_page_segment(ecryptfs_inode,
+ ecryptfs_page,
+ start_offset_in_page,
+ data_offset);
page_cache_release(ecryptfs_page);
if (rc) {
printk(KERN_ERR "%s: Error encrypting "
@@ -194,14 +202,16 @@
pos += num_bytes;
}
if ((offset + size) > ecryptfs_file_size) {
- i_size_write(ecryptfs_file->f_dentry->d_inode, (offset + size));
- rc = ecryptfs_write_inode_size_to_metadata(
- ecryptfs_file->f_dentry->d_inode);
- if (rc) {
- printk(KERN_ERR "Problem with "
- "ecryptfs_write_inode_size_to_metadata; "
- "rc = [%d]\n", rc);
- goto out;
+ i_size_write(ecryptfs_inode, (offset + size));
+ if (crypt_stat->flags & ECRYPTFS_ENCRYPTED) {
+ rc = ecryptfs_write_inode_size_to_metadata(
+ ecryptfs_inode);
+ if (rc) {
+ printk(KERN_ERR "Problem with "
+ "ecryptfs_write_inode_size_to_metadata; "
+ "rc = [%d]\n", rc);
+ goto out;
+ }
}
}
out: