On Tue, Jan 23, 2018 at 11:57 PM, Lawrence Brakmo <bra...@fb.com> wrote:
> Currently, a sock_ops BPF program can write the op field and all the
> reply fields (reply and replylong). This is a bug. The op field should
> not have been writeable and there is currently no way to use replylong
> field for indices >= 1. This patch enforces that only the reply field
> (which equals replylong[0]) is writeable.
Would this patch be more suitable for -net ?
>
> Fixes: 40304b2a1567 ("bpf: BPF support for sock_ops")
> Signed-off-by: Lawrence Brakmo <bra...@fb.com>
Acked-by: Yuchung Cheng <ych...@google.com>
> ---
> net/core/filter.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 0cf170f..c356ec0 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -3845,8 +3845,7 @@ static bool sock_ops_is_valid_access(int off, int size,
> {
> if (type == BPF_WRITE) {
> switch (off) {
> - case offsetof(struct bpf_sock_ops, op) ...
> - offsetof(struct bpf_sock_ops, replylong[3]):
> + case offsetof(struct bpf_sock_ops, reply):
> break;
> default:
> return false;
> --
> 2.9.5
>
