Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1428972AbdDYKdL (ORCPT ); Tue, 25 Apr 2017 06:33:11 -0400 Received: from mail-oi0-f53.google.com ([209.85.218.53]:36217 "EHLO mail-oi0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1428982AbdDYKdA (ORCPT ); Tue, 25 Apr 2017 06:33:00 -0400 MIME-Version: 1.0 In-Reply-To: <1493114155-12101-1-git-send-email-honli@redhat.com> References: <1493114155-12101-1-git-send-email-honli@redhat.com> From: Or Gerlitz Date: Tue, 25 Apr 2017 13:32:59 +0300 Message-ID: Subject: Re: [PATCH] IB/IPoIB: Check the headroom size To: Honggang LI , Erez Shitrit Cc: Doug Ledford , "Hefty, Sean" , Hal Rosenstock , Paolo Abeni , "linux-rdma@vger.kernel.org" , Linux Kernel , Linux Netdev List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1003 Lines: 26 On Tue, Apr 25, 2017 at 12:55 PM, Honggang LI wrote: > From: Honggang Li > > Minimal hard_header_len set by bond_compute_features is ETH_HLEN, which > is smaller than IPOIB_HARD_LEN. ipoib_hard_header should check the > size of headroom to avoid skb_under_panic. sounds terrible, ipoib bonding is supported since ~2007, thanks for reporting on that. > [ 122.871493] ipoib_hard_header: skb->head= ffff8808179d9400, skb->data= ffff8808179d9420, skb_headroom= 0x20 > [ 123.055400] bond0: Releasing backup interface mthca_ib1 > [ 123.560529] bond_compute_features:1112 bond0 bond_dev->hard_header_len = 14 > [ 123.568822] CPU: 0 PID: 12336 Comm: ifdown-ib Not tainted 4.9.0-debug #1 did you generate this trace by calling dump_stack or this is existing kernel code. > Fixes: fc791b633515 ('IB/ipoib: move back IB LL address into the hard header') this is more of WA to avoid some crash or failure but not fixing the actual problem Erez, can you comment? Or.