crypto: af_alg - fix race accessing cipher request

When invoking an asynchronous cipher operation, the invocation of the
callback may be performed before the subsequent operations in the
initial code path are invoked. The callback deletes the cipher request
data structure which implies that after the invocation of the
asynchronous cipher operation, this data structure must not be accessed
any more.

The setting of the return code size with the request data structure must
therefore be moved before the invocation of the asynchronous cipher
operation.

Fixes: e870456d8e ("crypto: algif_skcipher - overhaul memory management")
Fixes: d887c52d6a ("crypto: algif_aead - overhaul memory management")
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Stephan Mueller 2017-12-08 11:50:37 +01:00 committed by Herbert Xu
parent 9abffc6f2e
commit d53c513579
2 changed files with 10 additions and 10 deletions

View File

@ -291,6 +291,10 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
/* AIO operation */
sock_hold(sk);
areq->iocb = msg->msg_iocb;
/* Remember output size that will be generated. */
areq->outlen = outlen;
aead_request_set_callback(&areq->cra_u.aead_req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
af_alg_async_cb, areq);
@ -298,12 +302,8 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
crypto_aead_decrypt(&areq->cra_u.aead_req);
/* AIO operation in progress */
if (err == -EINPROGRESS || err == -EBUSY) {
/* Remember output size that will be generated. */
areq->outlen = outlen;
if (err == -EINPROGRESS || err == -EBUSY)
return -EIOCBQUEUED;
}
sock_put(sk);
} else {

View File

@ -125,6 +125,10 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
/* AIO operation */
sock_hold(sk);
areq->iocb = msg->msg_iocb;
/* Remember output size that will be generated. */
areq->outlen = len;
skcipher_request_set_callback(&areq->cra_u.skcipher_req,
CRYPTO_TFM_REQ_MAY_SLEEP,
af_alg_async_cb, areq);
@ -133,12 +137,8 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
/* AIO operation in progress */
if (err == -EINPROGRESS || err == -EBUSY) {
/* Remember output size that will be generated. */
areq->outlen = len;
if (err == -EINPROGRESS || err == -EBUSY)
return -EIOCBQUEUED;
}
sock_put(sk);
} else {