crypto: do not free algorithm before using
commit e5bde04ccce64d808f8b00a489a1fe5825d285cb upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/crypto/cfb.c b/crypto/cfb.c
index a0d68c0..20987d0 100644
--- a/crypto/cfb.c
+++ b/crypto/cfb.c
@@ -286,9 +286,8 @@
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 @@
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;