From aaa6452763cf944da72f16e0736554accb364703 Mon Sep 17 00:00:00 2001 From: "Nikita V. Shirokov" Date: Sun, 22 Apr 2018 21:16:48 -0700 Subject: [PATCH] bpf: fix virtio-net's length calc for XDP_PASS In commit 6870de435b90 ("bpf: make virtio compatible w/ bpf_xdp_adjust_tail") i didn't account for vi->hdr_len during new packet's length calculation after bpf_prog_run in receive_mergeable. because of this all packets, if they were passed to the kernel, were truncated by 12 bytes. Fixes:6870de435b90 ("bpf: make virtio compatible w/ bpf_xdp_adjust_tail") Reported-by: David Ahern Signed-off-by: Nikita V. Shirokov Acked-by: Jason Wang Signed-off-by: Daniel Borkmann --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 3b5991734118..f34794a76c4d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -765,7 +765,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, /* recalculate len if xdp.data or xdp.data_end were * adjusted */ - len = xdp.data_end - xdp.data; + len = xdp.data_end - xdp.data + vi->hdr_len; /* We can only create skb based on xdp_page. */ if (unlikely(xdp_page != page)) { rcu_read_unlock(); -- 2.30.2