crypto: seqiv - Handle EBUSY correctly

[ Upstream commit 32e62025e5 ]

As it is seqiv only handles the special return value of EINPROGERSS,
which means that in all other cases it will free data related to the
request.

However, as the caller of seqiv may specify MAY_BACKLOG, we also need
to expect EBUSY and treat it in the same way.  Otherwise backlogged
requests will trigger a use-after-free.

Fixes: 0a270321db ("[CRYPTO] seqiv: Add Sequence Number IV Generator")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

crypto/seqiv.c

@@ -23,7 +23,7 @@ static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
 	struct aead_request *subreq = aead_request_ctx(req);
 	struct crypto_aead *geniv;
 
-	if (err == -EINPROGRESS)
+	if (err == -EINPROGRESS || err == -EBUSY)
 		return;
 
 	if (err)