From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:42338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728329AbfC0SC1 (ORCPT ); Wed, 27 Mar 2019 14:02:27 -0400 From: Sasha Levin Subject: [PATCH AUTOSEL 5.0 016/262] xsk: fix to reject invalid flags in xsk_bind Date: Wed, 27 Mar 2019 13:57:51 -0400 Message-Id: <20190327180158.10245-16-sashal@kernel.org> In-Reply-To: <20190327180158.10245-1-sashal@kernel.org> References: <20190327180158.10245-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: xdp-newbies-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org, xdp-newbies@vger.kernel.org From: Björn Töpel [ Upstream commit f54ba391d88f5a5d032175b4c308c176e34b80b7 ] 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 Signed-off-by: Sasha Levin --- net/xdp/xsk.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 85e4fe4f18cc..f3031c8907d9 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; -- 2.19.1