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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 BDD0DECE58C for ; Wed, 9 Oct 2019 16:49:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0F6621848 for ; Wed, 9 Oct 2019 16:49:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731663AbfJIQtj (ORCPT ); Wed, 9 Oct 2019 12:49:39 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:35825 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731538AbfJIQti (ORCPT ); Wed, 9 Oct 2019 12:49:38 -0400 Received: from localhost.localdomain (238.210.broadband10.iol.cz [90.177.210.238]) (Authenticated sender: i.maximets@ovn.org) by relay11.mail.gandi.net (Postfix) with ESMTPSA id BE66E10000F; Wed, 9 Oct 2019 16:49:34 +0000 (UTC) From: Ilya Maximets To: netdev@vger.kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , "David S . Miller" , Jonathan Lemon , Andrii Nakryiko , Ilya Maximets Subject: [PATCH bpf v2] libbpf: fix passing uninitialized bytes to setsockopt Date: Wed, 9 Oct 2019 18:49:29 +0200 Message-Id: <20191009164929.17242-1-i.maximets@ovn.org> X-Mailer: git-send-email 2.17.1 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org '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 --- 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