linux-kernel - [PATCH 5/7] crypto: ccree: unmap buffer before copying IV

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Date:   Tue, 15 Jan 2019 15:43:15 +0200
From:   Gilad Ben-Yossef <gilad@...yossef.com>
To:     Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>
Cc:     stable@...r.kernel.org, linux-crypto@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 5/7] crypto: ccree: unmap buffer before copying IV

We were copying the last ciphertext block into the IV field
for CBC before removing the DMA mapping of the output buffer
with the result of the buffer sometime being out-of-sync cache
wise and were getting intermittent cases of bad output IV.

Fix it by moving the DMA buffer unmapping before the copy.

Signed-off-by: Gilad Ben-Yossef <gilad@...yossef.com>
Fixes: 00904aa0cd59 ("crypto: ccree - fix iv handling")
Cc: <stable@...r.kernel.org>
---
 drivers/crypto/ccree/cc_cipher.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccree/cc_cipher.c b/drivers/crypto/ccree/cc_cipher.c
index cc92b031fad1..98ea53524250 100644
--- a/drivers/crypto/ccree/cc_cipher.c
+++ b/drivers/crypto/ccree/cc_cipher.c
@@ -652,6 +652,8 @@ static void cc_cipher_complete(struct device *dev, void *cc_req, int err)
 	unsigned int ivsize = crypto_skcipher_ivsize(sk_tfm);
 	unsigned int len;
 
+	cc_unmap_cipher_request(dev, req_ctx, ivsize, src, dst);
+
 	switch (ctx_p->cipher_mode) {
 	case DRV_CIPHER_CBC:
 		/*
@@ -681,7 +683,6 @@ static void cc_cipher_complete(struct device *dev, void *cc_req, int err)
 		break;
 	}
 
-	cc_unmap_cipher_request(dev, req_ctx, ivsize, src, dst);
 	kzfree(req_ctx->iv);
 
 	skcipher_request_complete(req, err);
-- 
2.20.1