Commit c57b557b authored Mar 08, 2019 by Björn Töpel Committed by Daniel Borkmann Mar 08, 2019

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: 35fcde7f ("xsk: support for Tx")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent f54ba391

net/xdp/xsk_queue.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

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