5.4-stable review patch. If anyone has any objections, please let me know.
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From: Nicolas Dichtel nicolas.dichtel@6wind.com
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 nicolas.dichtel@6wind.com Signed-off-by: David S. Miller davem@davemloft.net Cc: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/netdevice.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3763,7 +3763,7 @@ static __always_inline int ____dev_forwa 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; }