From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Conole Subject: [PATCH v3 -next] net/core/dev: Warn on a too-short GRO frame Date: Sat, 2 Apr 2016 15:26:43 -0400 Message-ID: <1459625203-8637-1-git-send-email-aconole@redhat.com> To: netdev@vger.kernel.org, Joe Perches , Eric Dumazet Return-path: Received: from mail-qg0-f68.google.com ([209.85.192.68]:36403 "EHLO mail-qg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751607AbcDBT0x (ORCPT ); Sat, 2 Apr 2016 15:26:53 -0400 Received: by mail-qg0-f68.google.com with SMTP id n34so14230180qge.3 for ; Sat, 02 Apr 2016 12:26:52 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Aaron Conole When signaling that a GRO frame is ready to be processed, the network stack correctly checks length and aborts processing when a frame is less than 14 bytes. However, such a condition is really indicative of a broken driver, and should be loudly signaled, rather than silently dropped as the case is today. Convert the condition to use net_warn_ratelimited() to ensure the stack loudly complains about such broken drivers. Signed-off-by: Aaron Conole --- v2: * Switched from WARN_ON to net_warn_ratelimited v3: * Amend the string to include device name as a hint net/core/dev.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index b9bcbe7..273f10d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4663,6 +4663,8 @@ static struct sk_buff *napi_frags_skb(struct napi_struct *napi) if (unlikely(skb_gro_header_hard(skb, hlen))) { eth = skb_gro_header_slow(skb, hlen, 0); if (unlikely(!eth)) { + net_warn_ratelimited("%s: dropping impossible skb from %s\n", + __func__, napi->dev->name); napi_reuse_skb(napi, skb); return NULL; } -- 2.5.5