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| author | Pan Bian <bianpan2016@163.com> | 2018-11-22 18:00:16 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-11-29 14:53:59 +0800 |
| commit | e5bde04ccce64d808f8b00a489a1fe5825d285cb (patch) | |
| tree | ff071a695559c7343c9ca04744794332368e0ecd /crypto/cbc.c | |
| parent | 9f4debe38415583086ce814798eeb864aeb39551 (diff) | |
| download | linux-e5bde04ccce64d808f8b00a489a1fe5825d285cb.tar.bz2 | |
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: 79c65d179a40 ("crypto: cbc - Convert to skcipher")
Fixes: a7d85e06ed80 ("crypto: cfb - add support for Cipher FeedBack mode")
Fixes: 043a44001b9e ("crypto: pcbc - Convert to skcipher")
Cc: <stable@vger.kernel.org>
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/cbc.c')
| -rw-r--r-- | crypto/cbc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/crypto/cbc.c b/crypto/cbc.c index b761b1f9c6ca..dd5f332fd566 100644 --- a/crypto/cbc.c +++ b/crypto/cbc.c @@ -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; |