[PATCH] crypto: safexcel - Add error handling for dma_map_sg() calls

From: Nikita Zhandarovich
Date: Wed Nov 29 2023 - 10:21:56 EST


Macro dma_map_sg() may return 0 on error. This patch enables
checks in case of the macro failure and ensures unmapping of
previously mapped buffers with dma_unmap_sg().

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: 49186a7d9e46 ("crypto: inside_secure - Avoid dma map if size is zero")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>

drivers/crypto/inside-secure/safexcel_cipher.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/crypto/inside-secure/safexcel_cipher.c b/drivers/crypto/inside-secure/safexcel_cipher.c
index 272c28b5a088..ca660f31c15f 100644
--- a/drivers/crypto/inside-secure/safexcel_cipher.c
+++ b/drivers/crypto/inside-secure/safexcel_cipher.c
@@ -742,9 +742,9 @@ static int safexcel_send_req(struct crypto_async_request *base, int ring,
max(totlen_src, totlen_dst));
return -EINVAL;
}
- if (sreq->nr_src > 0)
- dma_map_sg(priv->dev, src, sreq->nr_src,
- DMA_BIDIRECTIONAL);
+ if ((sreq->nr_src > 0) &&
+ (!dma_map_sg(priv->dev, src, sreq->nr_src, DMA_BIDIRECTIONAL)))
+ return -ENOMEM;
} else {
if (unlikely(totlen_src && (sreq->nr_src <= 0))) {
dev_err(priv->dev, "Source buffer not large enough (need %d bytes)!",
@@ -752,8 +752,9 @@ static int safexcel_send_req(struct crypto_async_request *base, int ring,
return -EINVAL;
}

- if (sreq->nr_src > 0)
- dma_map_sg(priv->dev, src, sreq->nr_src, DMA_TO_DEVICE);
+ if ((sreq->nr_src > 0) &&
+ (!dma_map_sg(priv->dev, src, sreq->nr_src, DMA_TO_DEVICE)))
+ return -ENOMEM;

if (unlikely(totlen_dst && (sreq->nr_dst <= 0))) {
dev_err(priv->dev, "Dest buffer not large enough (need %d bytes)!",
@@ -762,9 +763,11 @@ static int safexcel_send_req(struct crypto_async_request *base, int ring,
goto unmap;
}

- if (sreq->nr_dst > 0)
- dma_map_sg(priv->dev, dst, sreq->nr_dst,
- DMA_FROM_DEVICE);
+ if ((sreq->nr_dst > 0) &&
+ (!dma_map_sg(priv->dev, dst, sreq->nr_dst, DMA_FROM_DEVICE))) {
+ ret = -ENOMEM;
+ goto unmap;
+ }
}

memcpy(ctx->base.ctxr->data, ctx->key, ctx->key_len);