Fixes for filename decryption and encrypted view plus a cleanup

- The filename decryption routines were, at times, writing a zero byte one
   character past the end of the filename buffer
 - The encrypted view feature attempted, and failed, to roll its own form of
   enforcing a read-only mount instead of letting the VFS enforce it
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Merge tag 'ecryptfs-3.19-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

Pull eCryptfs fixes from Tyler Hicks:
 "Fixes for filename decryption and encrypted view plus a cleanup

   - The filename decryption routines were, at times, writing a zero
     byte one character past the end of the filename buffer

   - The encrypted view feature attempted, and failed, to roll its own
     form of enforcing a read-only mount instead of letting the VFS
     enforce it"

* tag 'ecryptfs-3.19-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  eCryptfs: Remove buggy and unnecessary write in file name decode routine
  eCryptfs: Remove unnecessary casts when parsing packet lengths
  eCryptfs: Force RO mount when encrypted view is enabled
This commit is contained in:
Linus Torvalds 2014-12-19 18:15:12 -08:00
commit 298647e31a
4 changed files with 16 additions and 19 deletions

View File

@ -1917,7 +1917,6 @@ ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size,
break;
case 2:
dst[dst_byte_offset++] |= (src_byte);
dst[dst_byte_offset] = 0;
current_bit_offset = 0;
break;
}

View File

@ -190,23 +190,11 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
{
int rc = 0;
struct ecryptfs_crypt_stat *crypt_stat = NULL;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
struct dentry *ecryptfs_dentry = file->f_path.dentry;
/* Private value of ecryptfs_dentry allocated in
* ecryptfs_lookup() */
struct ecryptfs_file_info *file_info;
mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
&& ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
|| (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
|| (file->f_flags & O_APPEND))) {
printk(KERN_WARNING "Mount has encrypted view enabled; "
"files may only be read\n");
rc = -EPERM;
goto out;
}
/* Released in ecryptfs_release or end of function if failure */
file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
ecryptfs_set_file_private(file, file_info);

View File

@ -100,12 +100,12 @@ int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
(*size) = 0;
if (data[0] < 192) {
/* One-byte length */
(*size) = (unsigned char)data[0];
(*size) = data[0];
(*length_size) = 1;
} else if (data[0] < 224) {
/* Two-byte length */
(*size) = (((unsigned char)(data[0]) - 192) * 256);
(*size) += ((unsigned char)(data[1]) + 192);
(*size) = (data[0] - 192) * 256;
(*size) += data[1] + 192;
(*length_size) = 2;
} else if (data[0] == 255) {
/* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */

View File

@ -493,6 +493,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
{
struct super_block *s;
struct ecryptfs_sb_info *sbi;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
struct ecryptfs_dentry_info *root_info;
const char *err = "Getting sb failed";
struct inode *inode;
@ -511,6 +512,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
err = "Error parsing options";
goto out;
}
mount_crypt_stat = &sbi->mount_crypt_stat;
s = sget(fs_type, NULL, set_anon_super, flags, NULL);
if (IS_ERR(s)) {
@ -557,11 +559,19 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
/**
* Set the POSIX ACL flag based on whether they're enabled in the lower
* mount. Force a read-only eCryptfs mount if the lower mount is ro.
* Allow a ro eCryptfs mount even when the lower mount is rw.
* mount.
*/
s->s_flags = flags & ~MS_POSIXACL;
s->s_flags |= path.dentry->d_sb->s_flags & (MS_RDONLY | MS_POSIXACL);
s->s_flags |= path.dentry->d_sb->s_flags & MS_POSIXACL;
/**
* Force a read-only eCryptfs mount when:
* 1) The lower mount is ro
* 2) The ecryptfs_encrypted_view mount option is specified
*/
if (path.dentry->d_sb->s_flags & MS_RDONLY ||
mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
s->s_flags |= MS_RDONLY;
s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
s->s_blocksize = path.dentry->d_sb->s_blocksize;