Re: [dpdk-dev] [PATCH v3] app/testpmd: fix copying the name of the dynflag

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

On 1/30/2020 9:04 PM, Ori Kam wrote:
> When working with testpmd and setting the dynflag name, we copy the
> name given by the cmd to the dynflag name.
> 
> The issue is that the size of the dynflag name is smaller then the
> string used by testpmd.
> 
> This commit solves this issue by checking that the length of the requested
> flag name is not too long.
> 
> Coverity issue: 353610
> 
> Fixes: b57b66a97ebf ("app/testpmd: support mbuf dynamic flag")
> 
> Signed-off-by: Ori Kam <orika@mellanox.com>
> ---
> V3:
>  * Fix style issue.
> 
> V2:
>  * change to check the requested flag name.
> ---
>  app/test-pmd/cmdline.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
> index dab22bc..7ccc778 100644
> --- a/app/test-pmd/cmdline.c
> +++ b/app/test-pmd/cmdline.c
> @@ -18865,6 +18865,10 @@ struct cmd_config_tx_dynf_specific_result {
>  
>  	if (port_id_is_invalid(res->port_id, ENABLED_WARN))
>  		return;
> +	if (strlen(res->name) > sizeof(desc_flag.name)) {

Shouldn't it be ">=" since 'strlen' doesn't count terminating char.
It would be safer to use 'strnlen'.

> +		printf("Flag name too long\n");
> +		return;
> +	}
>  	flag = rte_mbuf_dynflag_lookup(res->name, NULL);
>  	if (flag <= 0) {
>  		strcpy(desc_flag.name, res->name);

And it would be nice to use 'strlcpy' here, to be sure target string will be
null terminated.