Re: [dpdk-dev] [PATCH] net/ring: fix unchecked return value

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 9/22/2020 6:20 PM, Kevin Laatz wrote:
> Add a check for the return value of the sscanf call in
> parse_internal_args(), returning an error if we don't get the expected
> result.
> 
> Coverity issue: 362049
> Fixes: 96cb19521147 ("net/ring: use EAL APIs in PMD specific API")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
> ---
>   drivers/net/ring/rte_eth_ring.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ring/rte_eth_ring.c b/drivers/net/ring/rte_eth_ring.c
> index 40fe1ca4ba..62060e46ce 100644
> --- a/drivers/net/ring/rte_eth_ring.c
> +++ b/drivers/net/ring/rte_eth_ring.c
> @@ -539,7 +539,8 @@ parse_internal_args(const char *key __rte_unused, const char *value,
>   	struct ring_internal_args **internal_args = data;
>   	void *args;
>   
> -	sscanf(value, "%p", &args);
> +	if (sscanf(value, "%p", &args) != 1)
> +		return -1;

I am aware that this is just to fix the coverity error to check the 
return value, BUT :)

The internal args is mainly to pass the information get by API 
('rte_eth_from_ring()') to ring probe. And the main information to pass 
is the ring.
It may be possible to pass the ring_name only and eliminate internal 
args completely, the driver already has a way to pass ring name:
"nodeaction=name:node:ATTACH" devargs.

If you have time, can you please check if it can be possible to fill and 
pass the nodeaction devargs in 'rte_eth_from_rings()' and eliminate the 
'internal' devargs completely?
If it works, as a bonus it will resolve above coverity issue by removing 
it :)