crypto: algif_aead - Fix bogus request dereference in completion function

The algif_aead completion function tries to deduce the aead_request
from the crypto_async_request argument.  This is broken because
the API does not guarantee that the same request will be pased to
the completion function.  Only the value of req->data can be used
in the completion function.

This patch fixes it by storing a pointer to sk in areq and using
that instead of passing in sk through req->data.

Fixes: 83094e5e9e ("crypto: af_alg - add async support to...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2017-04-10 17:59:07 +08:00
parent ef0579b64e
commit e6534aebb2

View File

@ -40,6 +40,7 @@ struct aead_async_req {
struct aead_async_rsgl first_rsgl;
struct list_head list;
struct kiocb *iocb;
struct sock *sk;
unsigned int tsgls;
char iv[];
};
@ -379,12 +380,10 @@ static ssize_t aead_sendpage(struct socket *sock, struct page *page,
static void aead_async_cb(struct crypto_async_request *_req, int err)
{
struct sock *sk = _req->data;
struct alg_sock *ask = alg_sk(sk);
struct aead_ctx *ctx = ask->private;
struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
struct aead_request *req = aead_request_cast(_req);
struct aead_request *req = _req->data;
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
struct aead_async_req *areq = GET_ASYM_REQ(req, tfm);
struct sock *sk = areq->sk;
struct scatterlist *sg = areq->tsgl;
struct aead_async_rsgl *rsgl;
struct kiocb *iocb = areq->iocb;
@ -447,11 +446,12 @@ static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg,
memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl));
INIT_LIST_HEAD(&areq->list);
areq->iocb = msg->msg_iocb;
areq->sk = sk;
memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm));
aead_request_set_tfm(req, tfm);
aead_request_set_ad(req, ctx->aead_assoclen);
aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
aead_async_cb, sk);
aead_async_cb, req);
used -= ctx->aead_assoclen;
/* take over all tx sgls from ctx */