Patch "gro: Enter slow-path if there is no tailroom" has been added to the 4.4-stable tree

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

gro: Enter slow-path if there is no tailroom

to the 4.4-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:
gro-enter-slow-path-if-there-is-no-tailroom.patch
and it can be found in the queue-4.4 subdirectory.

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

From: Herbert Xu <[email protected]>
Date: Tue, 10 Jan 2017 12:24:01 -0800
Subject: gro: Enter slow-path if there is no tailroom

From: Herbert Xu <[email protected]>

[ Upstream commit 1272ce87fa017ca4cf32920764d879656b7a005a ]

The GRO path has a fast-path where we avoid calling pskb_may_pull and pskb_expand by directly accessing frag0. However, this should only be done if we have enough tailroom in the skb as otherwise we'll have to expand it later anyway.

This patch adds the check by capping frag0_len with the skb tailroom.

---
 net/core/dev.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -4187,7 +4187,8 @@ static void skb_gro_reset_offset(struct
 	    pinfo->nr_frags &&
 	    !PageHighMem(skb_frag_page(frag0))) {
 		NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
-		NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0);
+		NAPI_GRO_CB(skb)->frag0_len = min(skb_frag_size(frag0),
+						  skb->end - skb->tail);
 	}
 }
 

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

queue-4.4/gro-disable-frag0-optimization-on-ipv6-ext-headers.patch queue-4.4/gro-enter-slow-path-if-there-is-no-tailroom.patch