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 C8416CCA478 for ; Thu, 2 Jun 2022 14:38:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236007AbiFBOiF (ORCPT ); Thu, 2 Jun 2022 10:38:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236006AbiFBOh6 (ORCPT ); Thu, 2 Jun 2022 10:37:58 -0400 Received: from mail-pf1-x431.google.com (mail-pf1-x431.google.com [IPv6:2607:f8b0:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BAF131229 for ; Thu, 2 Jun 2022 07:37:56 -0700 (PDT) Received: by mail-pf1-x431.google.com with SMTP id c196so4941205pfb.1 for ; Thu, 02 Jun 2022 07:37:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=Sk/LpREl6lCpYUK3sh4dhIYv+NwXzY+EQFNtou9uNgg=; b=WU//QHTddMEmbobKV3WmcaFVCVlqESjL4yadeBcxJG2Ehcb0sSYTsZ2ImwxNeLk/vm MlQdDacFExr4Y4YHDdLlFOOS1UjdqOIrJFDkP/uhF4qxxtDHANzfd/1htrEsoDczNBt9 pbsUknttci1Qm1XuPwq7iten0RYvQ3EgZAPklHaWN5NWPnYBt1zpZrUUMCnLDduM4fQZ Jf+eiPYLSvXYm/5oFexTJemCClME2J4GAt69BjH4gRvnso9TSvpmG5pJdtSKY1ajWgPO 24aLoQGMyZ221R2i8b0wtiAv/IeG1ozi7UfMDcsGOIeD7POBBFykhNSQ7/+AHwBJdikp NLMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=Sk/LpREl6lCpYUK3sh4dhIYv+NwXzY+EQFNtou9uNgg=; b=A88+qx9udRf3c5n8Jze9SJ6IivTwhX5Cb41xEXJIVyEpBAQfkbWB87zzCmxM6HHGON EkwChKTtwgabxQg+znYph5Qj4aWa0L406LLAV3emLRMtIUjaZcfTX0GhYjZ6OHM0nSwe 6nX/eR97FBJF3McEvlnBKlxLaI/hzVhoZuj67hThIc0Tsaqa2PaXIiBeVnqz3gRKbdI6 XhutdY+GMbIXL1ELQR4wpem01hctZHokalRG00lhS2jxZiS+I/HXLHKkk0pzPnQGYSy4 Icx4OKtoLhMgUHA3zOO4TIcSvFNboVuiVEMi3RafG+VI8AKIpxLP1r7ebBD5SvoSmKT1 ID1w== X-Gm-Message-State: AOAM530cTDZ7pnftEYVbV72JcXiKVK37d8DzASCvMqUb9sjQ72iYwFmo kFPnPQ2GzmBiP8BWk6SFe0s68g== X-Google-Smtp-Source: ABdhPJylye22XZAN19kga/OK9TT4aEC7VNrMVwD8tJrhsly5C9WmEfLmW7j0si2yIeXqk24ffGKw0Q== X-Received: by 2002:a63:f955:0:b0:3fc:cf92:cd26 with SMTP id q21-20020a63f955000000b003fccf92cd26mr4494997pgk.137.1654180675640; Thu, 02 Jun 2022 07:37:55 -0700 (PDT) Received: from [192.168.254.36] ([50.39.160.154]) by smtp.gmail.com with ESMTPSA id z14-20020a17090a170e00b001df239bab14sm3440275pjd.46.2022.06.02.07.37.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Jun 2022 07:37:54 -0700 (PDT) Message-ID: <41265f4d-45b4-a3a6-e0c0-5460d2a06377@linaro.org> Date: Thu, 2 Jun 2022 07:37:53 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v4] bpf: Fix KASAN use-after-free Read in compute_effective_progs Content-Language: en-US To: Andrii Nakryiko Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Networking , bpf , linux- stable , open list , syzbot+f264bffdfbd5614f3bb2@syzkaller.appspotmail.com References: <20220517180420.87954-1-tadeusz.struk@linaro.org> <7949d722-86e8-8122-e607-4b09944b76ae@linaro.org> From: Tadeusz Struk In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Hi Andrii, On 5/23/22 15:47, Andrii Nakryiko wrote: >> Hi Andrii, >> Do you have any more feedback? Does it look better to you now? > Hi, this is on my TODO list, but I need a bit more focused time to > think all this through and I haven't managed to get it in last week. > I'm worried about the percpu_ref_is_zero(&desc->bpf.refcnt) portion > and whether it can cause some skew in the calculated array index, I > need to look at this a bit more in depth. Sorry for the delay. Did you get a chance to look at this yet? -- Thanks, Tadeusz