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Subject[PATCH 29/35] crypto: ccree: don't map MAC key on stack
Date
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+
---
drivers/crypto/ccree/cc_hash.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/ccree/cc_hash.c b/drivers/crypto/ccree/cc_hash.c
index 36e9fb4141f8..a6abe4e3bb0e 100644
--- a/drivers/crypto/ccree/cc_hash.c
+++ b/drivers/crypto/ccree/cc_hash.c
@@ -69,6 +69,7 @@ struct cc_hash_alg {
struct hash_key_req_ctx {
u32 keylen;
dma_addr_t key_dma_addr;
+ u8 *key;
};

/* hash per-session context */
@@ -742,13 +743,20 @@ static int cc_hash_setkey(struct crypto_ahash *ahash, const u8 *key,
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",
@@ -899,6 +907,9 @@ static int cc_hash_setkey(struct crypto_ahash *ahash, const u8 *key,
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;
}

@@ -925,11 +936,16 @@ static int cc_xcbc_setkey(struct crypto_ahash *ahash,

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",
@@ -981,6 +997,8 @@ static int cc_xcbc_setkey(struct crypto_ahash *ahash,
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;
}

--
2.21.0
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