xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

eCryptfs: Fix data corruption when using ecryptfs_passthrough

Browse Source 
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>
This commit is contained in:
Tyler Hicks
2009-04-13 15:29:27 -05:00
parent 3a5203ab3c
commit 13a791b4e6
4 changed files with 41 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
fs/ecryptfs/read_write.c
View File

@@ -117,13 +117,15 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
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 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
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 @@ int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset,
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: