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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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