From c44b14469af07217074f6d83f08168a7aa438dd4 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Thu, 24 Jun 2021 10:05:05 +0200 Subject: [PATCH] dev_forward_skb: do not scrub skb mark within the same name space commit ff70202b2d1ad522275c6aadc8c53519b6a22c57 upstream. The goal is to keep the mark during a bpf_redirect(), like it is done for legacy encapsulation / decapsulation, when there is no x-netns. This was initially done in commit 213dd74aee76 ("skbuff: Do not scrub skb mark within the same name space"). When the call to skb_scrub_packet() was added in dev_forward_skb() (commit 8b27f27797ca ("skb: allow skb_scrub_packet() to be used by tunnels")), the second argument (xnet) was set to true to force a call to skb_orphan(). At this time, the mark was always cleanned up by skb_scrub_packet(), whatever xnet value was. This call to skb_orphan() was removed later in commit 9c4c325252c5 ("skbuff: preserve sock reference when scrubbing the skb."). But this 'true' stayed here without any real reason. Let's correctly set xnet in ____dev_forward_skb(), this function has access to the previous interface and to the new interface. Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller Cc: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman --- include/linux/netdevice.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 302abfc2a1f6..e814ce78a196 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3972,7 +3972,7 @@ static __always_inline int ____dev_forward_skb(struct net_device *dev, return NET_RX_DROP; } - skb_scrub_packet(skb, true); + skb_scrub_packet(skb, !net_eq(dev_net(dev), dev_net(skb->dev))); skb->priority = 0; return 0; }