This is a note to let you know that I've just added the patch titled

crypto: inside-secure - avoid unmapping DMA memory that was not mapped

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: crypto-inside-secure-avoid-unmapping-dma-memory-that-was-not-mapped.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From c957f8b3e2e54b29f53ef69decc87bbc858c9b58 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Antoine=20T=C3=A9nart?= antoine.tenart@free-electrons.com Date: Tue, 26 Dec 2017 17:21:16 +0100 Subject: crypto: inside-secure - avoid unmapping DMA memory that was not mapped

From: Antoine Tenart antoine.tenart@free-electrons.com

commit c957f8b3e2e54b29f53ef69decc87bbc858c9b58 upstream.

This patch adds a parameter in the SafeXcel ahash request structure to keep track of the number of SG entries mapped. This allows not to call dma_unmap_sg() when dma_map_sg() wasn't called in the first place. This also removes a warning when the debugging of the DMA-API is enabled in the kernel configuration: "DMA-API: device driver tries to free DMA memory it has not allocated".

Fixes: 1b44c5a60c13 ("crypto: inside-secure - add SafeXcel EIP197 crypto engine driver") Signed-off-by: Antoine Tenart antoine.tenart@free-electrons.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/crypto/inside-secure/safexcel_hash.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)

--- a/drivers/crypto/inside-secure/safexcel_hash.c +++ b/drivers/crypto/inside-secure/safexcel_hash.c @@ -34,6 +34,8 @@ struct safexcel_ahash_req { bool hmac; bool needs_inv;

+ int nents; + u8 state_sz; /* expected sate size, only set once */ u32 state[SHA256_DIGEST_SIZE / sizeof(u32)] __aligned(sizeof(u32));

@@ -152,8 +154,10 @@ static int safexcel_handle_req_result(st memcpy(areq->result, sreq->state, crypto_ahash_digestsize(ahash));

- dma_unmap_sg(priv->dev, areq->src, - sg_nents_for_len(areq->src, areq->nbytes), DMA_TO_DEVICE); + if (sreq->nents) { + dma_unmap_sg(priv->dev, areq->src, sreq->nents, DMA_TO_DEVICE); + sreq->nents = 0; + }

safexcel_free_context(priv, async, sreq->state_sz);

@@ -178,7 +182,7 @@ static int safexcel_ahash_send_req(struc struct safexcel_command_desc *cdesc, *first_cdesc = NULL; struct safexcel_result_desc *rdesc; struct scatterlist *sg; - int i, nents, queued, len, cache_len, extra, n_cdesc = 0, ret = 0; + int i, queued, len, cache_len, extra, n_cdesc = 0, ret = 0;

queued = len = req->len - req->processed; if (queued < crypto_ahash_blocksize(ahash)) @@ -248,15 +252,15 @@ static int safexcel_ahash_send_req(struc }

/* Now handle the current ahash request buffer(s) */ - nents = dma_map_sg(priv->dev, areq->src, - sg_nents_for_len(areq->src, areq->nbytes), - DMA_TO_DEVICE); - if (!nents) { + req->nents = dma_map_sg(priv->dev, areq->src, + sg_nents_for_len(areq->src, areq->nbytes), + DMA_TO_DEVICE); + if (!req->nents) { ret = -ENOMEM; goto cdesc_rollback; }

- for_each_sg(areq->src, sg, nents, i) { + for_each_sg(areq->src, sg, req->nents, i) { int sglen = sg_dma_len(sg);

/* Do not overflow the request */

Patches currently in stable-queue which might be from antoine.tenart@free-electrons.com are

queue-4.15/crypto-inside-secure-avoid-unmapping-dma-memory-that-was-not-mapped.patch queue-4.15/crypto-inside-secure-fix-hash-when-length-is-a-multiple-of-a-block.patch