xsk: fix to reject invalid options in Tx descriptor

Passing a non-existing option in the options member of struct
xdp_desc was, incorrectly, silently ignored. This patch addresses
that behavior, and drops any Tx descriptor with non-existing options.

We have examined existing user space code, and to our best knowledge,
no one is relying on the current incorrect behavior. AF_XDP is still
in its infancy, so from our perspective, the risk of breakage is very
low, and addressing this problem now is important.

Fixes: 35fcde7f8d ("xsk: support for Tx")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Björn Töpel 2019-03-08 08:57:27 +01:00 committed by Daniel Borkmann
parent f54ba391d8
commit c57b557b64
1 changed files with 2 additions and 2 deletions

View File

@ -174,8 +174,8 @@ static inline bool xskq_is_valid_desc(struct xsk_queue *q, struct xdp_desc *d)
if (!xskq_is_valid_addr(q, d->addr))
return false;
if (((d->addr + d->len) & q->chunk_mask) !=
(d->addr & q->chunk_mask)) {
if (((d->addr + d->len) & q->chunk_mask) != (d->addr & q->chunk_mask) ||
d->options) {
q->invalid_descs++;
return false;
}