Merge tag 'ecryptfs-3.12-rc1-crypt-ctx' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

Pull eCryptfs fixes from Tyler Hicks:
 "Two small fixes to the code that initializes the per-file crypto
  contexts"

* tag 'ecryptfs-3.12-rc1-crypt-ctx' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  ecryptfs: avoid ctx initialization race
  ecryptfs: remove check for if an array is NULL

1 files changed, 6 insertions, 10 deletions

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index d107576..c88e355 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -609,39 +609,35 @@ int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat)
 	char *full_alg_name;
 	int rc = -EINVAL;
 
-	if (!crypt_stat->cipher) {
-		ecryptfs_printk(KERN_ERR, "No cipher specified\n");
-		goto out;
-	}
 	ecryptfs_printk(KERN_DEBUG,
 			"Initializing cipher [%s]; strlen = [%d]; "
 			"key_size_bits = [%zd]\n",
 			crypt_stat->cipher, (int)strlen(crypt_stat->cipher),
 			crypt_stat->key_size << 3);
+	mutex_lock(&crypt_stat->cs_tfm_mutex);
 	if (crypt_stat->tfm) {
 		rc = 0;
-		goto out;
+		goto out_unlock;
 	}
-	mutex_lock(&crypt_stat->cs_tfm_mutex);
 	rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
 						    crypt_stat->cipher, "cbc");
 	if (rc)
 		goto out_unlock;
 	crypt_stat->tfm = crypto_alloc_ablkcipher(full_alg_name, 0, 0);
-	kfree(full_alg_name);
 	if (IS_ERR(crypt_stat->tfm)) {
 		rc = PTR_ERR(crypt_stat->tfm);
 		crypt_stat->tfm = NULL;
 		ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): "
 				"Error initializing cipher [%s]\n",
-				crypt_stat->cipher);
-		goto out_unlock;
+				full_alg_name);
+		goto out_free;
 	}
 	crypto_ablkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
 	rc = 0;
+out_free:
+	kfree(full_alg_name);
 out_unlock:
 	mutex_unlock(&crypt_stat->cs_tfm_mutex);
-out:
 	return rc;
 }