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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Gilad Ben-Yossef <gilad@benyossef.com>,
        Herbert Xu <herbert@gondor.apana.org.au>
Subject: [PATCH 5.4 171/232] crypto: ccree - only try to map auth tag if needed
Date:   Thu, 16 Apr 2020 15:24:25 +0200
Message-Id: <20200416131336.402131587@linuxfoundation.org>
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From: Gilad Ben-Yossef <gilad@benyossef.com>

commit 504e84abec7a635b861afd8d7f92ecd13eaa2b09 upstream.

Make sure to only add the size of the auth tag to the source mapping
for encryption if it is an in-place operation. Failing to do this
previously caused us to try and map auth size len bytes from a NULL
mapping and crashing if both the cryptlen and assoclen are zero.

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/crypto/ccree/cc_buffer_mgr.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/crypto/ccree/cc_buffer_mgr.c
+++ b/drivers/crypto/ccree/cc_buffer_mgr.c
@@ -1109,9 +1109,11 @@ int cc_map_aead_request(struct cc_drvdat
 	}
 
 	size_to_map = req->cryptlen + areq_ctx->assoclen;
-	if (areq_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_ENCRYPT)
+	/* If we do in-place encryption, we also need the auth tag */
+	if ((areq_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_ENCRYPT) &&
+	   (req->src == req->dst)) {
 		size_to_map += authsize;
-
+	}
 	if (is_gcm4543)
 		size_to_map += crypto_aead_ivsize(tfm);
 	rc = cc_map_sg(dev, req->src, size_to_map, DMA_BIDIRECTIONAL,