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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21404C433EF for ; Wed, 16 Mar 2022 04:00:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231822AbiCPEBb (ORCPT ); Wed, 16 Mar 2022 00:01:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbiCPEBa (ORCPT ); Wed, 16 Mar 2022 00:01:30 -0400 Received: from mail-il1-x136.google.com (mail-il1-x136.google.com [IPv6:2607:f8b0:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6915B4832A; Tue, 15 Mar 2022 21:00:17 -0700 (PDT) Received: by mail-il1-x136.google.com with SMTP id n16so786063ile.11; Tue, 15 Mar 2022 21:00:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=rSzgmk+B5Ar8ei69IOGqcC1Qk1yUbI7eByB01Wx0p6I=; b=pP5JYTkoc1Y3kyWz0sEb7RMEKSR9QwoKjSSgKdF7oKCLUkEqxztDffUqt7ULe9JuqQ DvY85KTODVlRhWEKwGnEKeN33CQEDzKnBxiJoWvJ1ttrih/Q9bNTWGXQFqS1Vo/pkn8R tFPgWZXfB/2gNSagNbmUMKrXII7XOh7ufEFnvLWmrDn6w45r/ZLAHFIqBvxMfNL1GWts RR2f4TztVYWFotKToGRQtFMT8TL9+ZLOsyvF97rSckWJXDIIjjRw5E7Vme4BPSyPt+ET UfINMbqGGQE2JIigkNROI8lfvALNfPWe2XyMsIstLE2NrTwwVwdvOItV20cfTECJPyJz GHHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=rSzgmk+B5Ar8ei69IOGqcC1Qk1yUbI7eByB01Wx0p6I=; b=SgI6qPRLvep36QyE61/1ey/xnOuKgsE6Ebfq/382rMGx2TXtM9RLvIINfluQRKD0TS pHTDzVkd0rraEMC59Oju0tTBLI8Rx2qmpJE/RixUy4I728KnTttQeNAgt8X9yW+uWYDl fyvoulBV1HGhuOJmj3aKUK6pqGlbcqa8mOVvMSpIxXMGzc8iszB+6t3Wx6Nn4KEkvz5B hXpsddERHsr/0x2EmG3OrIwFx0fR70NV8oRfqdTZEDkvazmwuQ4R55pPX8tFreViaoGy rBQ8xzxbZ2Hx46PvrqwCNMTKW8U8RrfzR6Iux811SFgiVDRylnBXvbv4ZPK9oFwkx8MF VHSg== X-Gm-Message-State: AOAM532hu63R01PMdF9kr1SLVkltXhzrr4tm4s04KeJPXQdjKDfaHojh D8htqNvXT2NEaFMBcC3uPXU= X-Google-Smtp-Source: ABdhPJzcQtEEU6gs4sIbbvZZqOiXwIIa8EE8ZqemjxybuOlWxKZK73jsohn2CtnA0MnNCtAmZLtl/Q== X-Received: by 2002:a92:130b:0:b0:2c5:66a6:cad8 with SMTP id 11-20020a92130b000000b002c566a6cad8mr22375500ilt.285.1647403216754; Tue, 15 Mar 2022 21:00:16 -0700 (PDT) Received: from localhost ([99.197.200.79]) by smtp.gmail.com with ESMTPSA id q197-20020a6b8ece000000b00648d615e80csm426357iod.41.2022.03.15.21.00.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Mar 2022 21:00:16 -0700 (PDT) Date: Tue, 15 Mar 2022 21:00:09 -0700 From: John Fastabend To: "liujian (CE)" , Martin KaFai Lau Cc: "ast@kernel.org" , "daniel@iogearbox.net" , "andrii@kernel.org" , "songliubraving@fb.com" , "yhs@fb.com" , "john.fastabend@gmail.com" , "kpsingh@kernel.org" , "davem@davemloft.net" , "kuba@kernel.org" , "sdf@google.com" , "netdev@vger.kernel.org" , "bpf@vger.kernel.org" Message-ID: <623160c966680_94df20819@john.notmuch> In-Reply-To: <4f937ace70a3458580c6242fa68ea549@huawei.com> References: <20220315123916.110409-1-liujian56@huawei.com> <20220315195822.sonic5avyizrufsv@kafai-mbp.dhcp.thefacebook.com> <4f937ace70a3458580c6242fa68ea549@huawei.com> Subject: RE: [PATCH bpf-next] net: Use skb->len to check the validity of the parameters in bpf_skb_load_bytes Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org liujian (CE) wrote: > > > > -----Original Message----- > > From: Martin KaFai Lau [mailto:kafai@fb.com] > > Sent: Wednesday, March 16, 2022 3:58 AM > > To: liujian (CE) > > Cc: ast@kernel.org; daniel@iogearbox.net; andrii@kernel.org; > > songliubraving@fb.com; yhs@fb.com; john.fastabend@gmail.com; > > kpsingh@kernel.org; davem@davemloft.net; kuba@kernel.org; > > sdf@google.com; netdev@vger.kernel.org; bpf@vger.kernel.org > > Subject: Re: [PATCH bpf-next] net: Use skb->len to check the validity of the > > parameters in bpf_skb_load_bytes > > > > On Tue, Mar 15, 2022 at 08:39:16PM +0800, Liu Jian wrote: > > > The data length of skb frags + frag_list may be greater than 0xffff, > > > so here use skb->len to check the validity of the parameters. > > What is the use case that needs to look beyond 0xffff ? > I use sockmap with strparser, the stm->strp.offset (the begin of one > application layer protocol message) maybe beyond 0xffff, but i need > load the message head to do something. This would explain skb_load_bytes but not the other two right? Also if we are doing this why not just remove those two checks in flow_dissector_load() I think skb_header_pointer() does duplicate checks. Please check.