eCryptfs: check for eCryptfs cipher support at mount
The issue occurs when eCryptfs is mounted with a cipher supported by
the crypto subsystem but not by eCryptfs. The mount succeeds and an
error does not occur until a write. This change checks for eCryptfs
cipher support at mount time.
Resolves Launchpad issue #338914, reported by Tyler Hicks in 03/2009.
https://bugs.launchpad.net/ecryptfs/+bug/338914
Signed-off-by: Tim Sally <tsally@atomicpeace.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index df217dc..923f6aa 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -279,6 +279,7 @@
char *fnek_src;
char *cipher_key_bytes_src;
char *fn_cipher_key_bytes_src;
+ u8 cipher_code;
*check_ruid = 0;
@@ -420,6 +421,18 @@
&& !fn_cipher_key_bytes_set)
mount_crypt_stat->global_default_fn_cipher_key_bytes =
mount_crypt_stat->global_default_cipher_key_size;
+
+ cipher_code = ecryptfs_code_for_cipher_string(
+ mount_crypt_stat->global_default_cipher_name,
+ mount_crypt_stat->global_default_cipher_key_size);
+ if (!cipher_code) {
+ ecryptfs_printk(KERN_ERR,
+ "eCryptfs doesn't support cipher: %s",
+ mount_crypt_stat->global_default_cipher_name);
+ rc = -EINVAL;
+ goto out;
+ }
+
mutex_lock(&key_tfm_list_mutex);
if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
NULL)) {