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=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 4EFE4C11F65 for ; Wed, 30 Jun 2021 09:21:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AEE061D0F for ; Wed, 30 Jun 2021 09:21:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233831AbhF3JX6 (ORCPT ); Wed, 30 Jun 2021 05:23:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233541AbhF3JX5 (ORCPT ); Wed, 30 Jun 2021 05:23:57 -0400 Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 105A3C061766 for ; Wed, 30 Jun 2021 02:21:29 -0700 (PDT) Received: by mail-lj1-x22f.google.com with SMTP id w11so2409463ljh.0 for ; Wed, 30 Jun 2021 02:21:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=references:user-agent:from:to:cc:subject:in-reply-to:date :message-id:mime-version; bh=0bgZwa4+MDdMGBtJ8KpBWEqd1dAeuKVVmAXrR5/PinE=; b=EEHK0RGTk3ViFVH1QaQoJEyzNlOU12OwZ/tm20dS8E9AHeybmvaFsZJLfahN5/wuaQ 2UTghkPXBmKqYnHrSAgNh4mY5GnsaWYuCE4+1RJsOG44GfhpmStOoPrigjU6EDSKTwzN 0uRXiQ3+tm5ndNZkJ7Zcu9MDZP+XO4o5VC6ys= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version; bh=0bgZwa4+MDdMGBtJ8KpBWEqd1dAeuKVVmAXrR5/PinE=; b=NU1/0cdYCwfuBCuWSL3pD7chOOuZh2HlCtJgqqTNBwFTywi3eKGZINy5vY/iJjFY4h h9zZL8JxnmAtRJnbQli7ljYPAVlm0u5olCCfLoEXLnGTEc+xfWofeWyIdkCwJfnZh/FZ tkcGLJUxeikrBrfZHzVlKL1KiMcrqwaeX7YlbmQ6F5mIWctBJ49Xfr8fNA7piOhC1cwm 4U76fFqor7EnAeqsf19AodjtJblf5QJao9THobElafgXXxddnT53m6FEEHqcH16ENwp/ MwdO2xsmvit88OyVy5WajsdmjxEmFS3z6TCEf0CPO7Kq08Y6OI1+xcW8hJosb/Y9wzSl jX+g== X-Gm-Message-State: AOAM533prYRugiyXe5EHmgKSg+orZEjUrbYnTWxtQ4XgdaV+CBmB1w6a WhnAwBI9OX/X1AOPaCDnpGIt7A== X-Google-Smtp-Source: ABdhPJyFBzQBHwTVCQ+0nwODrze7uFbsDwv47P6JzI3uSnqJBwH6MAcX1twT4v1dfepFo2H2jrOl7w== X-Received: by 2002:a2e:a78d:: with SMTP id c13mr7442575ljf.0.1625044887228; Wed, 30 Jun 2021 02:21:27 -0700 (PDT) Received: from cloudflare.com (79.191.58.233.ipv4.supernova.orange.pl. [79.191.58.233]) by smtp.gmail.com with ESMTPSA id i130sm1866108lfd.304.2021.06.30.02.21.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Jun 2021 02:21:26 -0700 (PDT) References: <20210629062029.13684-1-xiyou.wangcong@gmail.com> User-agent: mu4e 1.1.0; emacs 27.2 From: Jakub Sitnicki To: Cong Wang Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Cong Wang , Jiang Wang , Daniel Borkmann , John Fastabend , Lorenz Bauer Subject: Re: [Patch bpf] skmsg: check sk_rcvbuf limit before queuing to ingress_skb In-reply-to: <20210629062029.13684-1-xiyou.wangcong@gmail.com> Date: Wed, 30 Jun 2021 11:21:25 +0200 Message-ID: <878s2rso6i.fsf@cloudflare.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Jun 29, 2021 at 08:20 AM CEST, Cong Wang wrote: [...] > @@ -854,7 +854,8 @@ static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb) > return -EIO; > } > spin_lock_bh(&psock_other->ingress_lock); > - if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) { > + if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED) || > + atomic_read(&sk_other->sk_rmem_alloc) > sk_other->sk_rcvbuf) { > spin_unlock_bh(&psock_other->ingress_lock); > skb_bpf_redirect_clear(skb); > sock_drop(from->sk, skb); > @@ -930,7 +931,8 @@ static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb, > } > if (err < 0) { > spin_lock_bh(&psock->ingress_lock); > - if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) { > + if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED) && > + atomic_read(&sk_other->sk_rmem_alloc) <= sk_other->sk_rcvbuf) { > skb_queue_tail(&psock->ingress_skb, skb); > schedule_work(&psock->work); > err = 0; I belive access to sk_rcvbuf should be annotated with READ_ONCE (for KCSAN's sake) as we don't lock the egress socket. See 8265792bf887 [1] ("net: silence KCSAN warnings around sk_add_backlog() calls") for guidance. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8265792bf8871acc2d00fd03883d830e2249d395