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: 965a990984 ("xsk: add support for bind for Rx")
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 08:57:26 +01:00 committed by Daniel Borkmann
parent 243b4cdab9
commit f54ba391d8

View File

@ -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;