Re: [dpdk-dev] [PATCH v3] ethdev: check for invalid device name

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

On 3/14/2019 4:20 PM, Stephen Hemminger wrote:
> Do not allow creating a ethernet device with a name over the
> allowed maximum (or zero length). This is safer than silently truncating
> which is what happens now.
> 
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
> ---
> v3 -- fix whitespace issue
> 
>  lib/librte_ethdev/rte_ethdev.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 85c1794968dd..cf69daaf3224 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -438,6 +438,18 @@ rte_eth_dev_allocate(const char *name)
>  {
>  	uint16_t port_id;
>  	struct rte_eth_dev *eth_dev = NULL;
> +	size_t name_len;
> +
> +	name_len = strnlen(name, RTE_ETH_NAME_MAX_LEN);

'strlen' does not check against NULL pointer and it will crash if NULL provided.

This is internal API, so the input is not completely out of our control but
still as an API if we need to check zero length, shouldn't we check for NULL
pointer as well?

> +	if (name_len == 0) {
> +		RTE_ETHDEV_LOG(ERR, "Zero length Ethernet device name\n");
> +		return NULL;
> +	}
> +
> +	if (name_len >= RTE_ETH_NAME_MAX_LEN) {
> +		RTE_ETHDEV_LOG(ERR, "Ethernet device name is too long\n");
> +		return NULL;
> +	}
>  
>  	rte_eth_dev_shared_data_prepare();
>  
>