Commit f54ba391 authored Mar 08, 2019 by Björn Töpel Committed by Daniel Borkmann Mar 08, 2019

xsk: fix to reject invalid flags in xsk_bind



Passing a non-existing flag in the sxdp_flags member of struct
sockaddr_xdp was, incorrectly, silently ignored. This patch addresses
that behavior, and rejects any non-existing flags.

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: 965a9909 ("xsk: add support for bind for Rx")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent 243b4cda

net/xdp/xsk.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -407,6 +407,10 @@ static int xsk_bind(struct socket sock, struct sockaddr addr, int addr_len)
		if (sxdp->sxdp_family != AF_XDP)
		return -EINVAL;

		flags = sxdp->sxdp_flags;
		if (flags & ~(XDP_SHARED_UMEM \| XDP_COPY \| XDP_ZEROCOPY))
		return -EINVAL;

		mutex_lock(&xs->mutex);
		if (xs->dev) {
		err = -EBUSY;
		@@ -425,7 +429,6 @@ static int xsk_bind(struct socket sock, struct sockaddr addr, int addr_len)
		}

		qid = sxdp->sxdp_queue_id;
		flags = sxdp->sxdp_flags;

		if (flags & XDP_SHARED_UMEM) {
		struct xdp_sock *umem_xs;

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