[PATCH 5.8 076/633] crypto: algif_aead - Do not set MAY_BACKLOG on the async path

From: Greg Kroah-Hartman
Date: Tue Oct 27 2020 - 13:12:42 EST


From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

commit cbdad1f246dd98e6c9c32a6e5212337f542aa7e0 upstream.

The async path cannot use MAY_BACKLOG because it is not meant to
block, which is what MAY_BACKLOG does. On the other hand, both
the sync and async paths can make use of MAY_SLEEP.

Fixes: 83094e5e9e49 ("crypto: af_alg - add async support to...")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
crypto/algif_aead.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/crypto/algif_aead.c
+++ b/crypto/algif_aead.c
@@ -78,7 +78,7 @@ static int crypto_aead_copy_sgl(struct c
SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, null_tfm);

skcipher_request_set_sync_tfm(skreq, null_tfm);
- skcipher_request_set_callback(skreq, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ skcipher_request_set_callback(skreq, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
skcipher_request_set_crypt(skreq, src, dst, len, NULL);

@@ -291,19 +291,20 @@ static int _aead_recvmsg(struct socket *
areq->outlen = outlen;

aead_request_set_callback(&areq->cra_u.aead_req,
- CRYPTO_TFM_REQ_MAY_BACKLOG,
+ CRYPTO_TFM_REQ_MAY_SLEEP,
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)
+ if (err == -EINPROGRESS)
return -EIOCBQUEUED;

sock_put(sk);
} else {
/* Synchronous operation */
aead_request_set_callback(&areq->cra_u.aead_req,
+ CRYPTO_TFM_REQ_MAY_SLEEP |
CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &ctx->wait);
err = crypto_wait_req(ctx->enc ?