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authorStephan Mueller <smueller@chronox.de>2017-11-10 13:20:55 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2017-11-24 13:23:39 +0800
commit7d2c3f54e6f646887d019faa45f35d6fe9fe82ce (patch)
tree216af0cc45030069ed6131e529e080718f9c57f7 /crypto
parent8e1fa89aa8bc2870009b4486644e4a58f2e2a4f5 (diff)
download96b-common-7d2c3f54e6f646887d019faa45f35d6fe9fe82ce.tar.gz
crypto: af_alg - remove locking in async callback
The code paths protected by the socket-lock do not use or modify the socket in a non-atomic fashion. The actions pertaining the socket do not even need to be handled as an atomic operation. Thus, the socket-lock can be safely ignored. This fixes a bug regarding scheduling in atomic as the callback function may be invoked in interrupt context. In addition, the sock_hold is moved before the AIO encrypt/decrypt operation to ensure that the socket is always present. This avoids a tiny race window where the socket is unprotected and yet used by the AIO operation. Finally, the release of resources for a crypto operation is moved into a common function of af_alg_free_resources. Cc: <stable@vger.kernel.org> Fixes: e870456d8e7c8 ("crypto: algif_skcipher - overhaul memory management") Fixes: d887c52d6ae43 ("crypto: algif_aead - overhaul memory management") Reported-by: Romain Izard <romain.izard.pro@gmail.com> Signed-off-by: Stephan Mueller <smueller@chronox.de> Tested-by: Romain Izard <romain.izard.pro@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/af_alg.c21
-rw-r--r--crypto/algif_aead.c23
-rw-r--r--crypto/algif_skcipher.c23
3 files changed, 38 insertions, 29 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 85cea9de324a..358749c38894 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -1021,6 +1021,18 @@ unlock:
EXPORT_SYMBOL_GPL(af_alg_sendpage);
/**
+ * af_alg_free_resources - release resources required for crypto request
+ */
+void af_alg_free_resources(struct af_alg_async_req *areq)
+{
+ struct sock *sk = areq->sk;
+
+ af_alg_free_areq_sgls(areq);
+ sock_kfree_s(sk, areq, areq->areqlen);
+}
+EXPORT_SYMBOL_GPL(af_alg_free_resources);
+
+/**
* af_alg_async_cb - AIO callback handler
*
* This handler cleans up the struct af_alg_async_req upon completion of the
@@ -1036,18 +1048,13 @@ void af_alg_async_cb(struct crypto_async_request *_req, int err)
struct kiocb *iocb = areq->iocb;
unsigned int resultlen;
- lock_sock(sk);
-
/* Buffer size written by crypto operation. */
resultlen = areq->outlen;
- af_alg_free_areq_sgls(areq);
- sock_kfree_s(sk, areq, areq->areqlen);
- __sock_put(sk);
+ af_alg_free_resources(areq);
+ sock_put(sk);
iocb->ki_complete(iocb, err ? err : resultlen, 0);
-
- release_sock(sk);
}
EXPORT_SYMBOL_GPL(af_alg_async_cb);
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
index e2068b78993c..805f485ddf1b 100644
--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -283,12 +283,23 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
/* AIO operation */
+ sock_hold(sk);
areq->iocb = msg->msg_iocb;
aead_request_set_callback(&areq->cra_u.aead_req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
af_alg_async_cb, areq);
err = ctx->enc ? crypto_aead_encrypt(&areq->cra_u.aead_req) :
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;
+
+ return -EIOCBQUEUED;
+ }
+
+ sock_put(sk);
} else {
/* Synchronous operation */
aead_request_set_callback(&areq->cra_u.aead_req,
@@ -300,19 +311,9 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
&ctx->wait);
}
- /* AIO operation in progress */
- if (err == -EINPROGRESS) {
- sock_hold(sk);
-
- /* Remember output size that will be generated. */
- areq->outlen = outlen;
-
- return -EIOCBQUEUED;
- }
free:
- af_alg_free_areq_sgls(areq);
- sock_kfree_s(sk, areq, areq->areqlen);
+ af_alg_free_resources(areq);
return err ? err : outlen;
}
diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 9954b078f0b9..30cff827dd8f 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -117,6 +117,7 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
/* AIO operation */
+ sock_hold(sk);
areq->iocb = msg->msg_iocb;
skcipher_request_set_callback(&areq->cra_u.skcipher_req,
CRYPTO_TFM_REQ_MAY_SLEEP,
@@ -124,6 +125,16 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
err = ctx->enc ?
crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
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;
+
+ return -EIOCBQUEUED;
+ }
+
+ sock_put(sk);
} else {
/* Synchronous operation */
skcipher_request_set_callback(&areq->cra_u.skcipher_req,
@@ -136,19 +147,9 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
&ctx->wait);
}
- /* AIO operation in progress */
- if (err == -EINPROGRESS) {
- sock_hold(sk);
-
- /* Remember output size that will be generated. */
- areq->outlen = len;
-
- return -EIOCBQUEUED;
- }
free:
- af_alg_free_areq_sgls(areq);
- sock_kfree_s(sk, areq, areq->areqlen);
+ af_alg_free_resources(areq);
return err ? err : len;
}