crypto: gcm - simplify error handling in crypto_rfc4106_create()

Simplify the error handling in crypto_rfc4106_create() by taking
advantage of crypto_grab_aead() now handling an ERR_PTR() name and by
taking advantage of crypto_drop_aead() now accepting (as a no-op) a
spawn that hasn't been grabbed yet.

Conveniently, this eliminates the 'ccm_name' variable which was
incorrectly named (it should have been 'gcm_name').

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/gcm.c b/crypto/gcm.c
index 8e5c0ac..5560341 100644 (file)
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -840,7 +840,6 @@ static int crypto_rfc4106_create(struct crypto_template *tmpl,
        struct aead_instance *inst;
        struct crypto_aead_spawn *spawn;
        struct aead_alg *alg;
-       const char *ccm_name;
        int err;
 
        algt = crypto_get_attr_type(tb);
@@ -852,19 +851,15 @@ static int crypto_rfc4106_create(struct crypto_template *tmpl,
 
        mask = crypto_requires_sync(algt->type, algt->mask);
 
-       ccm_name = crypto_attr_alg_name(tb[1]);
-       if (IS_ERR(ccm_name))
-               return PTR_ERR(ccm_name);
-
        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;
 
        spawn = aead_instance_ctx(inst);
        err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
-                              ccm_name, 0, mask);
+                              crypto_attr_alg_name(tb[1]), 0, mask);
        if (err)
-               goto out_free_inst;
+               goto err_free_inst;
 
        alg = crypto_spawn_aead_alg(spawn);
 
@@ -872,11 +867,11 @@ static int crypto_rfc4106_create(struct crypto_template *tmpl,
 
        /* Underlying IV size must be 12. */
        if (crypto_aead_alg_ivsize(alg) != GCM_AES_IV_SIZE)
-               goto out_drop_alg;
+               goto err_free_inst;
 
        /* Not a stream cipher? */
        if (alg->base.cra_blocksize != 1)
-               goto out_drop_alg;
+               goto err_free_inst;
 
        err = -ENAMETOOLONG;
        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
@@ -885,7 +880,7 @@ static int crypto_rfc4106_create(struct crypto_template *tmpl,
            snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "rfc4106(%s)", alg->base.cra_driver_name) >=
            CRYPTO_MAX_ALG_NAME)
-               goto out_drop_alg;
+               goto err_free_inst;
 
        inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
        inst->alg.base.cra_priority = alg->base.cra_priority;
@@ -909,17 +904,11 @@ static int crypto_rfc4106_create(struct crypto_template *tmpl,
        inst->free = crypto_rfc4106_free;
 
        err = aead_register_instance(tmpl, inst);
-       if (err)
-               goto out_drop_alg;
-
-out:
+       if (err) {
+err_free_inst:
+               crypto_rfc4106_free(inst);
+       }
        return err;
-
-out_drop_alg:
-       crypto_drop_aead(spawn);
-out_free_inst:
-       kfree(inst);
-       goto out;
 }
 
 static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,