Patch "net: avoid skb_warn_bad_offload on IS_ERR" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

net: avoid skb_warn_bad_offload on IS_ERR

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-avoid-skb_warn_bad_offload-on-is_err.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Willem de Bruijn <[email protected]>
Date: Tue, 12 Dec 2017 11:39:04 -0500
Subject: net: avoid skb_warn_bad_offload on IS_ERR

From: Willem de Bruijn <[email protected]>

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.

---
 net/core/dev.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -2792,7 +2792,7 @@ 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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/net-avoid-skb_warn_bad_offload-on-is_err.patch