On Mon, Jul 27, 2020 at 7:30 PM Peilin Ye <yepeilin.cs@xxxxxxxxx> wrote:
>
> xsk_getsockopt() is copying uninitialized stack memory to userspace when
> `extra_stats` is `false`. Fix it by initializing `stats` with memset().
>
> Cc: stable@xxxxxxxxxxxxxxx
8aa5a33578e9 is not in stable branches yet, so we don't need to Cc stable.
> Fixes: 8aa5a33578e9 ("xsk: Add new statistics")
> Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
> ---
> net/xdp/xsk.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index 26e3bba8c204..acf001908a0d 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -844,6 +844,8 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
> bool extra_stats = true;
> size_t stats_size;
>
> + memset(&stats, 0, sizeof(stats));
> +
xsk.c doesn't include linux/string.h directly, so using memset may break
build for some config combinations. We can probably just use
struct xdp_statistics stats = {};
Thanks,
Song
> if (len < sizeof(struct xdp_statistics_v1)) {
> return -EINVAL;
> } else if (len < sizeof(stats)) {
> --
> 2.25.1
>
