From: Björn Töpel Date: Fri, 8 Mar 2019 07:57:26 +0000 (+0100) Subject: xsk: fix to reject invalid flags in xsk_bind X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=f54ba391d88f5a5d032175b4c308c176e34b80b7;p=openwrt%2Fstaging%2Fblogic.git 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: 965a99098443 ("xsk: add support for bind for Rx") Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann --- diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 6697084e3fdf..a14e8864e4fa 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -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;