Re: [PATCH v2] net/nfp: fix possible buffer overflow

[Alejandro Lucero <alejandro.lucero@netronome.com>]

On Fri, Mar 8, 2019 at 10:28 AM Pallantla Poornima <
pallantlax.poornima@intel.com> wrote:

> sprintf function is not secure as it doesn't check the length of string.
> More secure function snprintf is used.
>
> Fixes: 896c265ef9 ("net/nfp: use new CPP interface")
> Fixes: c4171b520b ("net/nfp: support PF multiport")
> Cc: stable@dpdk.org
>
> Signed-off-by: Pallantla Poornima <pallantlax.poornima@intel.com>
> ---
> v2: updated title as suggested.
> ---
>  drivers/net/nfp/nfp_net.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
> index a791e95e2..f63def5ef 100644
> --- a/drivers/net/nfp/nfp_net.c
> +++ b/drivers/net/nfp/nfp_net.c
> @@ -3318,9 +3318,9 @@ nfp_pf_create_dev(struct rte_pci_device *dev, int
> port, int ports,
>                 return -ENOMEM;
>
>         if (ports > 1)
> -               sprintf(port_name, "%s_port%d", dev->device.name, port);
> +               snprintf(port_name, 100, "%s_port%d", dev->device.name,
> port);
>         else
> -               sprintf(port_name, "%s", dev->device.name);
> +               strlcat(port_name, dev->device.name, 100);
>
>
>         if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
> @@ -3433,12 +3433,14 @@ nfp_fw_upload(struct rte_pci_device *dev, struct
> nfp_nsp *nsp, char *card)
>         /* Looking for firmware file in order of priority */
>
>         /* First try to find a firmware image specific for this device */
> -       sprintf(serial, "serial-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x",
> +       snprintf(serial, sizeof(serial),
> +                       "serial-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x",
>                 cpp->serial[0], cpp->serial[1], cpp->serial[2],
> cpp->serial[3],
>                 cpp->serial[4], cpp->serial[5], cpp->interface >> 8,
>                 cpp->interface & 0xff);
>
> -       sprintf(fw_name, "%s/%s.nffw", DEFAULT_FW_PATH, serial);
> +       snprintf(fw_name, sizeof(fw_name), "%s/%s.nffw", DEFAULT_FW_PATH,
> +                       serial);
>
>         PMD_DRV_LOG(DEBUG, "Trying with fw file: %s", fw_name);
>         fw_f = open(fw_name, O_RDONLY);
> @@ -3446,7 +3448,8 @@ nfp_fw_upload(struct rte_pci_device *dev, struct
> nfp_nsp *nsp, char *card)
>                 goto read_fw;
>
>         /* Then try the PCI name */
> -       sprintf(fw_name, "%s/pci-%s.nffw", DEFAULT_FW_PATH, dev->
> device.name);
> +       snprintf(fw_name, sizeof(fw_name), "%s/pci-%s.nffw",
> DEFAULT_FW_PATH,
> +                       dev->device.name);
>
>         PMD_DRV_LOG(DEBUG, "Trying with fw file: %s", fw_name);
>         fw_f = open(fw_name, O_RDONLY);
> @@ -3454,7 +3457,7 @@ nfp_fw_upload(struct rte_pci_device *dev, struct
> nfp_nsp *nsp, char *card)
>                 goto read_fw;
>
>         /* Finally try the card type and media */
> -       sprintf(fw_name, "%s/%s", DEFAULT_FW_PATH, card);
> +       snprintf(fw_name, sizeof(fw_name), "%s/%s", DEFAULT_FW_PATH, card);
>         PMD_DRV_LOG(DEBUG, "Trying with fw file: %s", fw_name);
>         fw_f = open(fw_name, O_RDONLY);
>         if (fw_f < 0) {
> @@ -3530,8 +3533,9 @@ nfp_fw_setup(struct rte_pci_device *dev, struct
> nfp_cpp *cpp,
>
>         PMD_DRV_LOG(INFO, "Port speed: %u", nfp_eth_table->ports[0].speed);
>
> -       sprintf(card_desc, "nic_%s_%dx%d.nffw", nfp_fw_model,
> -               nfp_eth_table->count, nfp_eth_table->ports[0].speed /
> 1000);
> +       snprintf(card_desc, sizeof(card_desc), "nic_%s_%dx%d.nffw",
> +                       nfp_fw_model, nfp_eth_table->count,
> +                       nfp_eth_table->ports[0].speed / 1000);
>
>         nsp = nfp_nsp_open(cpp);
>         if (!nsp) {
> --
> 2.17.2
>
>
I got a compilation error when applying this patch: strlcat can not be
found.

I guess this patch requires to check for system libraries versions.