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Date:   Fri, 13 Jan 2023 18:24:09 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH] crypto: essiv - Handle EBUSY correctly
Message-ID: <Y8ExSbhemaU2u+8P@gondor.apana.org.au>
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As it is essiv 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 essiv 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: be1eb7f78aa8 ("crypto: essiv - create wrapper template...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/essiv.c b/crypto/essiv.c
index e33369df9034..307eba74b901 100644
--- a/crypto/essiv.c
+++ b/crypto/essiv.c
@@ -171,7 +171,12 @@ static void essiv_aead_done(struct crypto_async_request *areq, int err)
 	struct aead_request *req = areq->data;
 	struct essiv_aead_request_ctx *rctx = aead_request_ctx(req);
 
+	if (err == -EINPROGRESS)
+		goto out;
+
 	kfree(rctx->assoc);
+
+out:
 	aead_request_complete(req, err);
 }
 
@@ -247,7 +252,7 @@ static int essiv_aead_crypt(struct aead_request *req, bool enc)
 	err = enc ? crypto_aead_encrypt(subreq) :
 		    crypto_aead_decrypt(subreq);
 
-	if (rctx->assoc && err != -EINPROGRESS)
+	if (rctx->assoc && err != -EINPROGRESS && err != -EBUSY)
 		kfree(rctx->assoc);
 	return err;
 }
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt