Commit fb90a1c8 authored by Ayush Sawal's avatar Ayush Sawal Committed by David S. Miller
Browse files

Crypto/chcr: Calculate src and dst sg lengths separately for dma map 



This patch calculates src and dst sg lengths separately for
dma mapping in case of aead operation.

This fixes a panic which occurs due to the accessing of a zero
length sg.
Panic:
[  138.173225] kernel BUG at drivers/iommu/intel-iommu.c:1184!

Signed-off-by: default avatarAyush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 934e36ec

drivers/crypto/chelsio/chcr_algo.c

+45 −18
Original line number Diff line number Diff line
@@ -2590,11 +2590,22 @@ int chcr_aead_dma_map(struct device *dev, 
	struct chcr_aead_reqctx  *reqctx = aead_request_ctx(req);

	struct crypto_aead *tfm = crypto_aead_reqtfm(req);

	unsigned int authsize = crypto_aead_authsize(tfm);

	int dst_size;

	int src_len, dst_len;



	dst_size = req->assoclen + req->cryptlen + (op_type ?

	/* calculate and handle src and dst sg length separately

	 * for inplace and out-of place operations

	 */

	if (req->src == req->dst) {

		src_len = req->assoclen + req->cryptlen + (op_type ?

							0 : authsize);

	if (!req->cryptlen || !dst_size)

		dst_len = src_len;

	} else {

		src_len = req->assoclen + req->cryptlen;

		dst_len = req->assoclen + req->cryptlen + (op_type ?

							-authsize : authsize);

	}



	if (!req->cryptlen || !src_len || !dst_len)

		return 0;

	reqctx->iv_dma = dma_map_single(dev, reqctx->iv, (IV + reqctx->b0_len),

					DMA_BIDIRECTIONAL);
@@ -2606,19 +2617,22 @@ int chcr_aead_dma_map(struct device *dev, 
		reqctx->b0_dma = 0;

	if (req->src == req->dst) {

		error = dma_map_sg(dev, req->src,

				sg_nents_for_len(req->src, dst_size),

				sg_nents_for_len(req->src, src_len),

					DMA_BIDIRECTIONAL);

		if (!error)

			goto err;

	} else {

		error = dma_map_sg(dev, req->src, sg_nents(req->src),

		error = dma_map_sg(dev, req->src,

				   sg_nents_for_len(req->src, src_len),

				   DMA_TO_DEVICE);

		if (!error)

			goto err;

		error = dma_map_sg(dev, req->dst, sg_nents(req->dst),

		error = dma_map_sg(dev, req->dst,

				   sg_nents_for_len(req->dst, dst_len),

				   DMA_FROM_DEVICE);

		if (!error) {

			dma_unmap_sg(dev, req->src, sg_nents(req->src),

			dma_unmap_sg(dev, req->src,

				     sg_nents_for_len(req->src, src_len),

				     DMA_TO_DEVICE);

			goto err;

		}
@@ -2637,23 +2651,36 @@ void chcr_aead_dma_unmap(struct device *dev, 
	struct chcr_aead_reqctx  *reqctx = aead_request_ctx(req);

	struct crypto_aead *tfm = crypto_aead_reqtfm(req);

	unsigned int authsize = crypto_aead_authsize(tfm);

	int dst_size;

	int src_len, dst_len;



	dst_size = req->assoclen + req->cryptlen + (op_type ?

	/* calculate and handle src and dst sg length separately

	 * for inplace and out-of place operations

	 */

	if (req->src == req->dst) {

		src_len = req->assoclen + req->cryptlen + (op_type ?

							0 : authsize);

	if (!req->cryptlen || !dst_size)

		dst_len = src_len;

	} else {

		src_len = req->assoclen + req->cryptlen;

		dst_len = req->assoclen + req->cryptlen + (op_type ?

						-authsize : authsize);

	}



	if (!req->cryptlen || !src_len || !dst_len)

		return;



	dma_unmap_single(dev, reqctx->iv_dma, (IV + reqctx->b0_len),

					DMA_BIDIRECTIONAL);

	if (req->src == req->dst) {

		dma_unmap_sg(dev, req->src,

			     sg_nents_for_len(req->src, dst_size),

			     sg_nents_for_len(req->src, src_len),

			     DMA_BIDIRECTIONAL);

	} else {

		dma_unmap_sg(dev, req->src, sg_nents(req->src),

		dma_unmap_sg(dev, req->src,

			     sg_nents_for_len(req->src, src_len),

			     DMA_TO_DEVICE);

		dma_unmap_sg(dev, req->dst, sg_nents(req->dst),

		dma_unmap_sg(dev, req->dst,

			     sg_nents_for_len(req->dst, dst_len),

			     DMA_FROM_DEVICE);

	}

}

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