Re: [PATCH] crypto: sun8i-ss: Fix memory leak of object d when dma_iv fails to map

[Corentin Labbe]

Le Tue, Mar 02, 2021 at 04:34:46PM +0000, Colin King a écrit :
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> In the case where the dma_iv mapping fails, the return error path leaks
> the memory allocated to object d.  Fix this by adding a new error return
> label and jumping to this to ensure d is free'd before the return.
> 
> Addresses-Coverity: ("Resource leak")
> Fixes: ac2614d721de ("crypto: sun8i-ss - Add support for the PRNG")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
>  drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c
> index 08a1473b2145..3191527928e4 100644
> --- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c
> +++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c
> @@ -103,7 +103,8 @@ int sun8i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
>  	dma_iv = dma_map_single(ss->dev, ctx->seed, ctx->slen, DMA_TO_DEVICE);
>  	if (dma_mapping_error(ss->dev, dma_iv)) {
>  		dev_err(ss->dev, "Cannot DMA MAP IV\n");
> -		return -EFAULT;
> +		err = -EFAULT;
> +		goto err_free;
>  	}
>  
>  	dma_dst = dma_map_single(ss->dev, d, todo, DMA_FROM_DEVICE);
> @@ -167,6 +168,7 @@ int sun8i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
>  		memcpy(ctx->seed, d + dlen, ctx->slen);
>  	}
>  	memzero_explicit(d, todo);
> +err_free:
>  	kfree(d);
>  
>  	return err;
> -- 
> 2.30.0
> 
Hello

Tested-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
Acked-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>

Thanks