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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 DCDB1C10F03 for ; Fri, 22 Mar 2019 19:59:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADBE6218FE for ; Fri, 22 Mar 2019 19:59:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ryLukK2t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726603AbfCVT7L (ORCPT ); Fri, 22 Mar 2019 15:59:11 -0400 Received: from mail-vk1-f202.google.com ([209.85.221.202]:44559 "EHLO mail-vk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725999AbfCVT7K (ORCPT ); Fri, 22 Mar 2019 15:59:10 -0400 Received: by mail-vk1-f202.google.com with SMTP id x207so1246307vke.11 for ; Fri, 22 Mar 2019 12:59:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=dvSFwX/cwTHRxA/HGGtK6nnCPtwgKpV/trwkfNlFVyQ=; b=ryLukK2tFSWTS7CigBR714CUpNUMrblcn/zmr784wnCxbYE5HlVsfR79CQzgxefrgm g2ohMw/ELbxAA0SlaMML8kke4Hmz88GuMZeQ3Tm1PnrlZ56TKdmCdeUUERAgTQsIWuMP H4Mye2yM6x+0Zy4eyLV9YWt1U5WaJFjV27LMbGHtJprpIlF0cz4v5SjYQLzP9yHeGzLA nyO3lE2MecEj6vtqdDapE3UUppwS/4glG/1w6Nna4z4h+wJ2BVBbti/Ds8krO5cKD3os 9Ne4VijjRhqq1+MmisLNSSH6nvSsSdXjCDOX9mlo5MLYqIElzIlKpf/O9UhkHeRJG3rZ uUFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=dvSFwX/cwTHRxA/HGGtK6nnCPtwgKpV/trwkfNlFVyQ=; b=K1OkQ7H/d5y9MKHfT4S/YSsg3/Kesvuf380on5yz1semT9/nPcequdKRxhdpsfvNcm NZrEtw46ylTtHbp4bmbvd2rpEdASYc9jq5F3pp2/6DxbUzYlJT9C61g0PHDEN3DmoUnh kMDoHN8EixBipmLZNFeEOyYBx40eCm1q+0Z21ETuDNPHsf+4keT3BuzbYXBQUWd9Wk/Y UgSB7iM51BvLsH3k4dMvTuekR1CR3ZIbUquPNtgkduKyDBXrgpShwI4iTPpPXOyGiXR8 LDcHeGWsPdJ+UmL1VRFtY812JHAqH9Wqbrr/l+0bFv7QicVGpaksxrEom0YS0GIu+pRa 04Tw== X-Gm-Message-State: APjAAAX9TwYoTo+x0RwDM00sbiWlEvtKYyxCBrabkKpUiDCAP/K0tzV5 juuyzONsl/zFA146g++kmtpCF7anKEjxTC19hp6jblyZzBaL/bO6Ns4Lh1XCQUPoPw1Hr1IgVW3 Bd0KXNZtI8d6dK7pYcDxwtYfckOa42lcyGctI7/AMV4NjTcPYeQ2aLA== X-Google-Smtp-Source: APXvYqxSZhoOgr6Wtay6fTPzOWH6Q69yMg4NTnZEokDaF8i3d+nWTVdEjsLTAWQMkqDgL+ClG/AEZho= X-Received: by 2002:a67:f790:: with SMTP id j16mr7135940vso.232.1553284748746; Fri, 22 Mar 2019 12:59:08 -0700 (PDT) Date: Fri, 22 Mar 2019 12:58:56 -0700 In-Reply-To: <20190322195903.162516-1-sdf@google.com> Message-Id: <20190322195903.162516-2-sdf@google.com> Mime-Version: 1.0 References: <20190322195903.162516-1-sdf@google.com> X-Mailer: git-send-email 2.21.0.392.gf8f6787159e-goog Subject: [RFC bpf-next v3 1/8] flow_dissector: allow access only to a subset of __sk_buff fields From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, simon.horman@netronome.com, willemb@google.com, peterpenkov96@gmail.com, Stanislav Fomichev Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Use whitelist instead of a blacklist and allow only a small set of fields that might be relevant in the context of flow dissector: * protocol * vlan_present * vlan_tci * vlan_proto This is required for the eth_get_headlen case where we have only a chunk of data to dissect (i.e. trying to read the other skb fields doesn't make sense). Signed-off-by: Stanislav Fomichev --- net/core/filter.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 647c63a7b25b..62a7a2f50200 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6613,14 +6613,8 @@ static bool flow_dissector_is_valid_access(int off, int size, const struct bpf_prog *prog, struct bpf_insn_access_aux *info) { - if (type == BPF_WRITE) { - switch (off) { - case bpf_ctx_range_till(struct __sk_buff, cb[0], cb[4]): - break; - default: - return false; - } - } + if (type == BPF_WRITE) + return false; switch (off) { case bpf_ctx_range(struct __sk_buff, data): @@ -6632,11 +6626,12 @@ static bool flow_dissector_is_valid_access(int off, int size, case bpf_ctx_range_ptr(struct __sk_buff, flow_keys): info->reg_type = PTR_TO_FLOW_KEYS; break; - case bpf_ctx_range(struct __sk_buff, tc_classid): - case bpf_ctx_range(struct __sk_buff, data_meta): - case bpf_ctx_range_till(struct __sk_buff, family, local_port): - case bpf_ctx_range(struct __sk_buff, tstamp): - case bpf_ctx_range(struct __sk_buff, wire_len): + case bpf_ctx_range(struct __sk_buff, protocol): + case bpf_ctx_range(struct __sk_buff, vlan_present): + case bpf_ctx_range(struct __sk_buff, vlan_tci): + case bpf_ctx_range(struct __sk_buff, vlan_proto): + break; + default: return false; } -- 2.21.0.392.gf8f6787159e-goog