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authorJesper Dangaard Brouer <brouer@redhat.com>2019-08-01 20:00:31 +0200
committerDavid S. Miller <davem@davemloft.net>2019-08-05 11:17:40 -0700
commit065af355470519bd184019a93ac579f22b036045 (patch)
tree8646d4782ad35e0fce6e8ebcecc3896fd694154d
parent13978d1e73d2fcfb6addcf3392707ad68fa88ccb (diff)
net: fix bpf_xdp_adjust_head regression for generic-XDP
When generic-XDP was moved to a later processing step by commit 458bf2f224f0 ("net: core: support XDP generic on stacked devices.") a regression was introduced when using bpf_xdp_adjust_head. The issue is that after this commit the skb->network_header is now changed prior to calling generic XDP and not after. Thus, if the header is changed by XDP (via bpf_xdp_adjust_head), then skb->network_header also need to be updated again. Fix by calling skb_reset_network_header(). Fixes: 458bf2f224f0 ("net: core: support XDP generic on stacked devices.") Reported-by: Brandon Cazander <brandon.cazander@multapplied.net> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/dev.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 2f341b850845..0891f499c1bb 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4374,12 +4374,17 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
act = bpf_prog_run_xdp(xdp_prog, xdp);
+ /* check if bpf_xdp_adjust_head was used */
off = xdp->data - orig_data;
- if (off > 0)
- __skb_pull(skb, off);
- else if (off < 0)
- __skb_push(skb, -off);
- skb->mac_header += off;
+ if (off) {
+ if (off > 0)
+ __skb_pull(skb, off);
+ else if (off < 0)
+ __skb_push(skb, -off);
+
+ skb->mac_header += off;
+ skb_reset_network_header(skb);
+ }
/* check if bpf_xdp_adjust_tail was used. it can only "shrink"
* pckt.