[PATCH AUTOSEL 4.19 30/31] crypto: xts - simplify error handling in ->create()

From: Sasha Levin
Date: Thu May 14 2020 - 15:03:26 EST


From: Eric Biggers <ebiggers@xxxxxxxxxx>

[ Upstream commit 732e540953477083082e999ff553622c59cffd5f ]

Simplify the error handling in the XTS template's ->create() function 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@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
crypto/xts.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/crypto/xts.c b/crypto/xts.c
index ccf55fbb8bc2d..a19965a0fe932 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -449,15 +449,15 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)

err = -EINVAL;
if (alg->base.cra_blocksize != XTS_BLOCK_SIZE)
- goto err_drop_spawn;
+ goto err_free_inst;

if (crypto_skcipher_alg_ivsize(alg))
- goto err_drop_spawn;
+ goto err_free_inst;

err = crypto_inst_setname(skcipher_crypto_instance(inst), "xts",
&alg->base);
if (err)
- goto err_drop_spawn;
+ goto err_free_inst;

err = -EINVAL;
cipher_name = alg->base.cra_name;
@@ -470,20 +470,20 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)

len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
if (len < 2 || len >= sizeof(ctx->name))
- goto err_drop_spawn;
+ goto err_free_inst;

if (ctx->name[len - 1] != ')')
- goto err_drop_spawn;
+ goto err_free_inst;

ctx->name[len - 1] = 0;

if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"xts(%s)", ctx->name) >= CRYPTO_MAX_ALG_NAME) {
err = -ENAMETOOLONG;
- goto err_drop_spawn;
+ goto err_free_inst;
}
} else
- 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;
@@ -507,17 +507,11 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
inst->free = free;

err = skcipher_register_instance(tmpl, inst);
- if (err)
- goto err_drop_spawn;
-
-out:
- return err;
-
-err_drop_spawn:
- crypto_drop_skcipher(&ctx->spawn);
+ if (err) {
err_free_inst:
- kfree(inst);
- goto out;
+ free(inst);
+ }
+ return err;
}

static struct crypto_template crypto_tmpl = {
--
2.20.1