[PATCH 4.19 142/220] crypto: mxs-dcp - Fix AES issues

Greg Kroah-Hartman
2019-11-22T11:02:34Z

From: Radu Solea <radu.solea@nxp.com>

[ Upstream commit fadd7a6e616b89c7f4f7bfa7b824f290bab32c3c ]

The DCP driver does not obey cryptlen, when doing android CTS this
results in passing to hardware input stream lengths which are not
multiple of block size.

Add a check to prevent future erroneous stream lengths from reaching the
hardware and adjust the scatterlist walking code to obey cryptlen.

Also properly copy-out the IV for chaining.

Signed-off-by: Radu Solea <radu.solea@nxp.com>
Signed-off-by: Franck LENORMAND <franck.lenormand@nxp.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/crypto/mxs-dcp.c | 33 +++++++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index 3425ccc012168..b926098f70ffd 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -225,6 +225,12 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
DCP_BUF_SZ, DMA_FROM_DEVICE);

+ if (actx->fill % AES_BLOCK_SIZE) {
+ dev_err(sdcp->dev, "Invalid block size!\n");
+ ret = -EINVAL;
+ goto aes_done_run;
+ }
+
/* Fill in the DMA descriptor. */
desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
MXS_DCP_CONTROL0_INTERRUPT |
@@ -254,6 +260,7 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,

ret = mxs_dcp_start_dma(actx);

+aes_done_run:
dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
DMA_TO_DEVICE);
dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
@@ -280,13 +287,15 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)

uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
uint32_t dst_off = 0;
+ uint32_t last_out_len = 0;

uint8_t *key = sdcp->coh->aes_key;

int ret = 0;
int split = 0;
- unsigned int i, len, clen, rem = 0;
+ unsigned int i, len, clen, rem = 0, tlen = 0;
int init = 0;
+ bool limit_hit = false;

actx->fill = 0;

@@ -305,6 +314,11 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
for_each_sg(req->src, src, nents, i) {
src_buf = sg_virt(src);
len = sg_dma_len(src);
+ tlen += len;
+ limit_hit = tlen > req->nbytes;
+
+ if (limit_hit)
+ len = req->nbytes - (tlen - len);

do {
if (actx->fill + len > out_off)
@@ -321,13 +335,15 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
* If we filled the buffer or this is the last SG,
* submit the buffer.
*/
- if (actx->fill == out_off || sg_is_last(src)) {
+ if (actx->fill == out_off || sg_is_last(src) ||
+ limit_hit) {
ret = mxs_dcp_run_aes(actx, req, init);
if (ret)
return ret;
init = 0;

out_tmp = out_buf;
+ last_out_len = actx->fill;
while (dst && actx->fill) {
if (!split) {
dst_buf = sg_virt(dst);
@@ -350,6 +366,19 @@ static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
}
}
} while (len);
+
+ if (limit_hit)
+ break;
+ }
+
+ /* Copy the IV for CBC for chaining */
+ if (!rctx->ecb) {
+ if (rctx->enc)
+ memcpy(req->info, out_buf+(last_out_len-AES_BLOCK_SIZE),
+ AES_BLOCK_SIZE);
+ else
+ memcpy(req->info, in_buf+(last_out_len-AES_BLOCK_SIZE),
+ AES_BLOCK_SIZE);
}

return ret;
--
2.20.1