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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 B8682ECE58D for ; Wed, 9 Oct 2019 16:55:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9062B21848 for ; Wed, 9 Oct 2019 16:55:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ik9UQ1pV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731694AbfJIQzH (ORCPT ); Wed, 9 Oct 2019 12:55:07 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:42749 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731145AbfJIQzG (ORCPT ); Wed, 9 Oct 2019 12:55:06 -0400 Received: by mail-qk1-f193.google.com with SMTP id f16so2830353qkl.9; Wed, 09 Oct 2019 09:55:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2/HF9NREfSQkdboNiYLB4mdV2BC4zZWqkjbH6CrigBU=; b=Ik9UQ1pVjDXAXl5D9zROUvPBuhjWeO0V8nn6PnzCOIuP5EQuq5LQEaSrM+cyyPW3qp faauOXKazJwuaxqCKuYJfs+WkOjQEb4T/JMn/m8tGie6IxEYLvTp7KeUI6KfkKfudlw6 GITXuCJTf4PhMkMgXjVhtQfUB5bVwmkOdwm7R499I9enV9JTtSajL0hfMfrZx3pH2NtL woDtjvZ4TuDQotmDSoHv4MJWWA/N6i+7d3rwvvdoV/8m9iYYvioqdqZbdwEUb56AlyZB FMz6K+Tp6XkJlIntRYhqhh0YNvzlcLSoST9pjwVQhDsNB7Tpe3VXZNsZ4HKmNUychf3q 9AAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=2/HF9NREfSQkdboNiYLB4mdV2BC4zZWqkjbH6CrigBU=; b=ZqNA9w+1CefhFQskq0jnIHxmDbWPKxoE5ZCvN1DTR+cpDyr8bmf5ywpuLk2+lbMMfr f90G6WnlXns4CNgMpo/UP2L95t3XZ+we4dyaSpMabgsjTEH1kJssfIaY1Zh60g+emir7 mAF3akPX0HfTUVNlyfoKfeePqShc3IYLxBgQsaRgulkwp+Bg1Mh0BNMWcN8EN7loEnhk 7ubGKQX3aS7wrVWdx99gOXM/MwiUKGqapZsDnGoxSdaDvwOKY15G3w8s8XhdWDli7vFw OpdQX2OnM40Ab/A2plw21OUdB9SOcQlFTf7zVCYNa825gH7ZA0fiXRq7ihhU8R2qNqAZ VQ1Q== X-Gm-Message-State: APjAAAXRQKMeLo9F+DwN5HLOH0SuXb55FsNGoF7LaUQgisW75IZ6OhHJ KYHa/0d7NJ+F9D1ITqAV/0xe8foR1n7uhfsRgbM= X-Google-Smtp-Source: APXvYqwkjEP6LQDwqyHgGNWPt2O8X8oEf9t3UY72mJKFPYOpn1GVrTNy2vlG4+DasgIr1qwwNWVKWBVGof7jwzagf7U= X-Received: by 2002:a37:520a:: with SMTP id g10mr4604504qkb.39.1570640103797; Wed, 09 Oct 2019 09:55:03 -0700 (PDT) MIME-Version: 1.0 References: <20191009164929.17242-1-i.maximets@ovn.org> In-Reply-To: <20191009164929.17242-1-i.maximets@ovn.org> From: Andrii Nakryiko Date: Wed, 9 Oct 2019 09:54:52 -0700 Message-ID: Subject: Re: [PATCH bpf v2] libbpf: fix passing uninitialized bytes to setsockopt To: Ilya Maximets Cc: Networking , bpf , open list , Alexei Starovoitov , Daniel Borkmann , "David S . Miller" , Jonathan Lemon Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Oct 9, 2019 at 9:49 AM Ilya Maximets wrote: > > 'struct xdp_umem_reg' has 4 bytes of padding at the end that makes > valgrind complain about passing uninitialized stack memory to the > syscall: > > Syscall param socketcall.setsockopt() points to uninitialised byte(s) > at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so) > by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172) > Uninitialised value was created by a stack allocation > at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140) > > Padding bytes appeared after introducing of a new 'flags' field. > memset() is required to clear them. > > Fixes: 10d30e301732 ("libbpf: add flags to umem config") > Signed-off-by: Ilya Maximets > --- > Thanks! Acked-by: Andrii Nakryiko > Version 2: > * Struct initializer replaced with explicit memset(). [Andrii] > > tools/lib/bpf/xsk.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c > index a902838f9fcc..9d5348086203 100644 > --- a/tools/lib/bpf/xsk.c > +++ b/tools/lib/bpf/xsk.c > @@ -163,6 +163,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, > umem->umem_area = umem_area; > xsk_set_umem_config(&umem->config, usr_config); > > + memset(&mr, 0, sizeof(mr)); > mr.addr = (uintptr_t)umem_area; > mr.len = size; > mr.chunk_size = umem->config.frame_size; > -- > 2.17.1 >