eCryptfs: release mutex on hash error path

Release the crypt_stat hash mutex on allocation error. Check for error
conditions when doing crypto hash calls.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Reported-by: Kazuki Ohta <kazuki.ohta@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ecryptfs/crypto.c

@@ -115,11 +115,29 @@ static int ecryptfs_calculate_md5(char *dst,
 		}
 		crypt_stat->hash_tfm = desc.tfm;
 	}
-	crypto_hash_init(&desc);
-	crypto_hash_update(&desc, &sg, len);
-	crypto_hash_final(&desc, dst);
-	mutex_unlock(&crypt_stat->cs_hash_tfm_mutex);
+	rc = crypto_hash_init(&desc);
+	if (rc) {
+		printk(KERN_ERR
+		       "%s: Error initializing crypto hash; rc = [%d]\n",
+		       __FUNCTION__, rc);
+		goto out;
+	}
+	rc = crypto_hash_update(&desc, &sg, len);
+	if (rc) {
+		printk(KERN_ERR
+		       "%s: Error updating crypto hash; rc = [%d]\n",
+		       __FUNCTION__, rc);
+		goto out;
+	}
+	rc = crypto_hash_final(&desc, dst);
+	if (rc) {
+		printk(KERN_ERR
+		       "%s: Error finalizing crypto hash; rc = [%d]\n",
+		       __FUNCTION__, rc);
+		goto out;
+	}
 out:
+	mutex_unlock(&crypt_stat->cs_hash_tfm_mutex);
 	return rc;
 }