4.9-stable review patch. If anyone has any objections, please let me know.
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From: Willem de Bruijn willemb@google.com
commit 8d74e9f88d65af8bb2e095aff506aa6eac755ada upstream.
skb_warn_bad_offload warns when packets enter the GSO stack that require skb_checksum_help or vice versa. Do not warn on arbitrary bad packets. Packet sockets can craft many. Syzkaller was able to demonstrate another one with eth_type games.
In particular, suppress the warning when segmentation returns an error, which is for reasons other than checksum offload.
See also commit 36c92474498a ("net: WARN if skb_checksum_help() is called on skb requiring segmentation") for context on this warning.
Signed-off-by: Willem de Bruijn willemb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/core/dev.c +++ b/net/core/dev.c @@ -2763,7 +2763,7 @@ struct sk_buff *__skb_gso_segment(struct
segs = skb_mac_gso_segment(skb, features);
- if (unlikely(skb_needs_check(skb, tx_path))) + if (unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs))) skb_warn_bad_offload(skb);
return segs;