From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 112CCC433E1 for ; Wed, 29 Jul 2020 00:52:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D00E5207E8 for ; Wed, 29 Jul 2020 00:52:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bfMHrDNj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730972AbgG2Aw4 (ORCPT ); Tue, 28 Jul 2020 20:52:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730837AbgG2Awz (ORCPT ); Tue, 28 Jul 2020 20:52:55 -0400 Received: from mail-oo1-xc2f.google.com (mail-oo1-xc2f.google.com [IPv6:2607:f8b0:4864:20::c2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B88CC061794 for ; Tue, 28 Jul 2020 17:52:55 -0700 (PDT) Received: by mail-oo1-xc2f.google.com with SMTP id x1so2017091oox.6 for ; Tue, 28 Jul 2020 17:52:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=FQKh6BDyrUAvdCbRkRoCWIwTvs02e1A4z4+hyJcCeYc=; b=bfMHrDNjRDJzP637Ny1jxdVnVrLBDUP/0SWUTzFX0Fd/EOqUJ7j6mZBax2+ryXNGEK 8SBRi3zyD7mF/u/4MnKI5U4Sm2UkxG/+xxOQX4ItIYdKgsagKvXvNpVviNZKfIfIbUq1 urtGTKEPdzepU5y9a49joRcOhTSJNVq5dp7kN2um3WQqfG4ZAzZUfbTP0/44vsJTYiDJ ELH7qkipiigniwpJeh+h7YrP/v923b1JqEQ5MjsCMZwe2EDkw6AV0tEmMtD1a1k2/zuX VXYamobnaIV+AjdIx4jD/xCNsYsObyVUxfnnBKfl6tJLmtPO04QLl1HDa8fV+bhG/k0n 325A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=FQKh6BDyrUAvdCbRkRoCWIwTvs02e1A4z4+hyJcCeYc=; b=SWXjBsjugnhryvR6fPF0ME5P9UdjNof1X1ppFakO5RSsar2MWFN7Nb0Lhkt8x/ofl4 OGdF0adRrbuxRD3HbtdaBMCOCToYGeTOUJHv3nRQbDYqFUcLG1Q4JR8wroD1yLxXN8d6 kw4g5JV8UK/h8avKzU2M9G0VBOZPXrkDWPYFHnJy5WgiU4m8DZfpbI9y8JGhvBBlpSE+ zGGuQiT9INqn/XQzL5Z7QrXGzlEYodfozk9p9G+jaUh8vqxbrJmq3WiHh6s66ByA7oxh GVjo6UQnqGXbxffr/jzbn3WWR/f8WEbrKhaoGv76xK+5njxIgfwiFTkllhKNQhpPJXf2 xlWg== X-Gm-Message-State: AOAM5317pKxIDaUSfY31kfo9kxtHb/F5ZIm3yk6CBwr7e7JmPfmyaaZ1 hej0s3n/ZyjTueNj4M6h0FJkqnerjbsL4jPAWLMlGRwRWxY= X-Google-Smtp-Source: ABdhPJxDGKMeML03pyUpPJr8pqcsGWOJsjX0I+dZl4PF472qk0SNTqlA3vYYVIzK1/3bM66m8cFOA27AlHUmXXOSNnk= X-Received: by 2002:a4a:e5d9:: with SMTP id r25mr1510956oov.90.1595983974796; Tue, 28 Jul 2020 17:52:54 -0700 (PDT) MIME-Version: 1.0 From: Ashutosh Grewal Date: Tue, 28 Jul 2020 17:52:44 -0700 Message-ID: Subject: Bug: ip utility fails to show routes with large # of multipath next-hops To: davem@davemloft.net, netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello David and all, I hope this is the correct way to report a bug. I observed this problem with 256 v4 next-hops or 128 v6 next-hops (or 128 or so # of v4 next-hops with labels). Here is an example - root@a6be8c892bb7:/# ip route show 2.2.2.2 Error: Buffer too small for object. Dump terminated Kernel details (though I recall running into the same problem on 4.4* kernel as well) - root@ubuntu-vm:/# uname -a Linux ch1 5.4.0-33-generic #37-Ubuntu SMP Thu May 21 12:53:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux I think the problem may be to do with the size of the skbuf being allocated as part of servicing the netlink request. static int netlink_dump(struct sock *sk) { skb = alloc_skb(...) Thanks, Ashutosh