From: Phil Sutter
> Sent: 17 August 2017 18:09
> To: Stephen Hemminger
> Cc: netdev@vger.kernel.org
> Subject: [iproute PATCH v2 1/7] ipntable: Make sure filter.name is
> NULL-terminated
>
> Signed-off-by: Phil Sutter <p...@nwl.cc>
> ---
> ip/ipntable.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/ip/ipntable.c b/ip/ipntable.c
> index 879626ee4f491..7be1f04d33d90 100644
> --- a/ip/ipntable.c
> +++ b/ip/ipntable.c
> @@ -633,7 +633,8 @@ static int ipntable_show(int argc, char **argv)
> } else if (strcmp(*argv, "name") == 0) {
> NEXT_ARG();
>
> - strncpy(filter.name, *argv, sizeof(filter.name));
> + strncpy(filter.name, *argv, sizeof(filter.name) - 1);
> + filter.name[sizeof(filter.name) - 1] = '\0';
Why not check for overflow instead?
if (filter.name[sizeof(filter.name) - 1])
usage("filer name too long");
David
