Re: [PATCH] [v2] crypto: ccp - fix memleak in ccp_init_dm_workarea

[Tom Lendacky <thomas.lendacky@xxxxxxx>]

On 11/26/23 21:47, Dinghao Liu wrote:
> When dma_map_single() fails, wa->address is supposed to be freed
> by the callers of ccp_init_dm_workarea() through ccp_dm_free().
> However, many of the call spots don't expect to have to call
> ccp_dm_free() on failure of ccp_init_dm_workarea(), which may
> lead to a memleak. Let's free wa->address in ccp_init_dm_workarea()
> when dma_map_single() fails.
>
> Fixes: 63b945091a07 ("crypto: ccp - CCP device driver and interface support")
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>

Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>

> ---
>
> Changelog:
>
> v2: -Improve the commit message.
>      -Set wa->address to NULL after kfree() to prevent double-free.
> ---
>   drivers/crypto/ccp/ccp-ops.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
> index aa4e1a500691..cb8e99936abb 100644
> --- a/drivers/crypto/ccp/ccp-ops.c
> +++ b/drivers/crypto/ccp/ccp-ops.c
> @@ -179,8 +179,11 @@ static int ccp_init_dm_workarea(struct ccp_dm_workarea *wa,
>   
>   		wa->dma.address = dma_map_single(wa->dev, wa->address, len,
>   						 dir);
> -		if (dma_mapping_error(wa->dev, wa->dma.address))
> +		if (dma_mapping_error(wa->dev, wa->dma.address)) {
> +			kfree(wa->address);
> +			wa->address = NULL;
>   			return -ENOMEM;
> +		}
>   
>   		wa->dma.length = len;
>   	}