Commit e5bde04c authored by Pan Bian's avatar Pan Bian Committed by Herbert Xu

crypto: do not free algorithm before using

In multiple functions, the algorithm fields are read after its reference
is dropped through crypto_mod_put. In this case, the algorithm memory
may be freed, resulting in use-after-free bugs. This patch delays the
put operation until the algorithm is never used.

Fixes: 79c65d17 ("crypto: cbc - Convert to skcipher")
Fixes: a7d85e06 ("crypto: cfb - add support for Cipher FeedBack mode")
Fixes: 043a4400 ("crypto: pcbc - Convert to skcipher")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarPan Bian <bianpan2016@163.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 9f4debe3
......@@ -140,9 +140,8 @@ static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
spawn = skcipher_instance_ctx(inst);
err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
CRYPTO_ALG_TYPE_MASK);
crypto_mod_put(alg);
if (err)
goto err_free_inst;
goto err_put_alg;
err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg);
if (err)
......@@ -174,12 +173,15 @@ static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)
err = skcipher_register_instance(tmpl, inst);
if (err)
goto err_drop_spawn;
crypto_mod_put(alg);
out:
return err;
err_drop_spawn:
crypto_drop_spawn(spawn);
err_put_alg:
crypto_mod_put(alg);
err_free_inst:
kfree(inst);
goto out;
......
......@@ -286,9 +286,8 @@ static int crypto_cfb_create(struct crypto_template *tmpl, struct rtattr **tb)
spawn = skcipher_instance_ctx(inst);
err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
CRYPTO_ALG_TYPE_MASK);
crypto_mod_put(alg);
if (err)
goto err_free_inst;
goto err_put_alg;
err = crypto_inst_setname(skcipher_crypto_instance(inst), "cfb", alg);
if (err)
......@@ -317,12 +316,15 @@ static int crypto_cfb_create(struct crypto_template *tmpl, struct rtattr **tb)
err = skcipher_register_instance(tmpl, inst);
if (err)
goto err_drop_spawn;
crypto_mod_put(alg);
out:
return err;
err_drop_spawn:
crypto_drop_spawn(spawn);
err_put_alg:
crypto_mod_put(alg);
err_free_inst:
kfree(inst);
goto out;
......
......@@ -244,9 +244,8 @@ static int crypto_pcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
spawn = skcipher_instance_ctx(inst);
err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst),
CRYPTO_ALG_TYPE_MASK);
crypto_mod_put(alg);
if (err)
goto err_free_inst;
goto err_put_alg;
err = crypto_inst_setname(skcipher_crypto_instance(inst), "pcbc", alg);
if (err)
......@@ -275,12 +274,15 @@ static int crypto_pcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
err = skcipher_register_instance(tmpl, inst);
if (err)
goto err_drop_spawn;
crypto_mod_put(alg);
out:
return err;
err_drop_spawn:
crypto_drop_spawn(spawn);
err_put_alg:
crypto_mod_put(alg);
err_free_inst:
kfree(inst);
goto out;
......
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