crypto: cts - simplify error handling in crypto_cts_create()

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

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

diff --git a/crypto/cts.c b/crypto/cts.c
index 48188adc8e91c3407cda1b7549ecf9f96eaf8ac3..5e005c4f0221589ddf19e3cd40def39f7ac3a22f 100644 (file)
--- a/crypto/cts.c
+++ b/crypto/cts.c
@@ -327,7 +327,6 @@ static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb)
        struct skcipher_instance *inst;
        struct crypto_attr_type *algt;
        struct skcipher_alg *alg;
-       const char *cipher_name;
        u32 mask;
        int err;
 
@@ -340,10 +339,6 @@ static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb)
 
        mask = crypto_requires_sync(algt->type, algt->mask);
 
-       cipher_name = crypto_attr_alg_name(tb[1]);
-       if (IS_ERR(cipher_name))
-               return PTR_ERR(cipher_name);
-
        inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
        if (!inst)
                return -ENOMEM;
@@ -351,7 +346,7 @@ static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb)
        spawn = skcipher_instance_ctx(inst);
 
        err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
-                                  cipher_name, 0, mask);
+                                  crypto_attr_alg_name(tb[1]), 0, mask);
        if (err)
                goto err_free_inst;
 
@@ -359,15 +354,15 @@ static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb)
 
        err = -EINVAL;
        if (crypto_skcipher_alg_ivsize(alg) != alg->base.cra_blocksize)
-               goto err_drop_spawn;
+               goto err_free_inst;
 
        if (strncmp(alg->base.cra_name, "cbc(", 4))
-               goto err_drop_spawn;
+               goto err_free_inst;
 
        err = crypto_inst_setname(skcipher_crypto_instance(inst), "cts",
                                  &alg->base);
        if (err)
-               goto err_drop_spawn;
+               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;
@@ -391,17 +386,11 @@ static int crypto_cts_create(struct crypto_template *tmpl, struct rtattr **tb)
        inst->free = crypto_cts_free;
 
        err = skcipher_register_instance(tmpl, inst);
-       if (err)
-               goto err_drop_spawn;
-
-out:
-       return err;
-
-err_drop_spawn:
-       crypto_drop_skcipher(spawn);
+       if (err) {
 err_free_inst:
-       kfree(inst);
-       goto out;
+               crypto_cts_free(inst);
+       }
+       return err;
 }
 
 static struct crypto_template crypto_cts_tmpl = {