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Subject[PATCH 4.19 046/105] crypto: ccree - dont map MAC key on stack
Date
From: Gilad Ben-Yossef <gilad@benyossef.com>

commit 874e163759f27e0a9988c5d1f4605e3f25564fd2 upstream.

The MAC hash key might be passed to us on stack. Copy it to
a slab buffer before mapping to gurantee proper DMA mapping.

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_hash.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

--- a/drivers/crypto/ccree/cc_hash.c
+++ b/drivers/crypto/ccree/cc_hash.c
@@ -64,6 +64,7 @@ struct cc_hash_alg {
struct hash_key_req_ctx {
u32 keylen;
dma_addr_t key_dma_addr;
+ u8 *key;
};

/* hash per-session context */
@@ -724,13 +725,20 @@ static int cc_hash_setkey(struct crypto_
ctx->key_params.keylen = keylen;
ctx->key_params.key_dma_addr = 0;
ctx->is_hmac = true;
+ ctx->key_params.key = NULL;

if (keylen) {
+ ctx->key_params.key = kmemdup(key, keylen, GFP_KERNEL);
+ if (!ctx->key_params.key)
+ return -ENOMEM;
+
ctx->key_params.key_dma_addr =
- dma_map_single(dev, (void *)key, keylen, DMA_TO_DEVICE);
+ dma_map_single(dev, (void *)ctx->key_params.key, keylen,
+ DMA_TO_DEVICE);
if (dma_mapping_error(dev, ctx->key_params.key_dma_addr)) {
dev_err(dev, "Mapping key va=0x%p len=%u for DMA failed\n",
- key, keylen);
+ ctx->key_params.key, keylen);
+ kzfree(ctx->key_params.key);
return -ENOMEM;
}
dev_dbg(dev, "mapping key-buffer: key_dma_addr=%pad keylen=%u\n",
@@ -881,6 +889,9 @@ out:
dev_dbg(dev, "Unmapped key-buffer: key_dma_addr=%pad keylen=%u\n",
&ctx->key_params.key_dma_addr, ctx->key_params.keylen);
}
+
+ kzfree(ctx->key_params.key);
+
return rc;
}

@@ -907,11 +918,16 @@ static int cc_xcbc_setkey(struct crypto_

ctx->key_params.keylen = keylen;

+ ctx->key_params.key = kmemdup(key, keylen, GFP_KERNEL);
+ if (!ctx->key_params.key)
+ return -ENOMEM;
+
ctx->key_params.key_dma_addr =
- dma_map_single(dev, (void *)key, keylen, DMA_TO_DEVICE);
+ dma_map_single(dev, ctx->key_params.key, keylen, DMA_TO_DEVICE);
if (dma_mapping_error(dev, ctx->key_params.key_dma_addr)) {
dev_err(dev, "Mapping key va=0x%p len=%u for DMA failed\n",
key, keylen);
+ kzfree(ctx->key_params.key);
return -ENOMEM;
}
dev_dbg(dev, "mapping key-buffer: key_dma_addr=%pad keylen=%u\n",
@@ -963,6 +979,8 @@ static int cc_xcbc_setkey(struct crypto_
dev_dbg(dev, "Unmapped key-buffer: key_dma_addr=%pad keylen=%u\n",
&ctx->key_params.key_dma_addr, ctx->key_params.keylen);

+ kzfree(ctx->key_params.key);
+
return rc;
}


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