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 d10757635b9c..c88e355f7635 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;
 }