From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , "David S. Miller" Subject: [PATCH 3.10 70/86] net-gro: reset skb->truesize in napi_reuse_skb() Date: Wed, 28 May 2014 21:37:45 -0700 Message-Id: <20140529043522.942097198@linuxfoundation.org> In-Reply-To: <20140529043513.451722422@linuxfoundation.org> References: <20140529043513.451722422@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit e33d0ba8047b049c9262fdb1fcafb93cb52ceceb ] Recycling skb always had been very tough... This time it appears GRO layer can accumulate skb->truesize adjustments made by drivers when they attach a fragment to skb. skb_gro_receive() can only subtract from skb->truesize the used part of a fragment. I spotted this problem seeing TcpExtPruneCalled and TcpExtTCPRcvCollapsed that were unexpected with a recent kernel, where TCP receive window should be sized properly to accept traffic coming from a driver not overshooting skb->truesize. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 1 + 1 file changed, 1 insertion(+) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3898,6 +3898,7 @@ static void napi_reuse_skb(struct napi_s skb->vlan_tci = 0; skb->dev = napi->dev; skb->skb_iif = 0; + skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); napi->skb = skb; }