From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3BA3338BB2 for ; Tue, 19 Sep 2023 08:39:58 +0000 (UTC) Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-32003aae100so1727357f8f.0 for ; Tue, 19 Sep 2023 01:39:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695112797; x=1695717597; darn=lists.linux.dev; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=JrX/o9IaaLd8C3/27VSA5k/8nslPmD25D5g+cKSefCE=; b=NG9GJTh+x70eFQ+UooARr56YiZGE8dBM88IxO1T/YAbEqn7P5+fpWmc9++Kdhu9sD8 RCoCtarVOCTeVDGCFMjIeUdlOBCfRGvJhuz08w1Dpp164WyVv34xswq735iK38zH5voo gBMTwt5GJvKrd60zxyVVRw5MtGT53yIjPDVF4hJW/OcsxJ4mtkj03YXMptzIVHBesSF1 V+AMDDnzcXVKR73BtI++GSObEw7L7RTlyfhFReRtAzoRK87cgfP3BhDDUnBr2j7SHgRW VbWnmYwC3TS1+jeSJTqmYyFy2xJMDwYXCEQfWmCuxnM2ZK5ufG6solPGT5DeDSA275HJ KEhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695112797; x=1695717597; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JrX/o9IaaLd8C3/27VSA5k/8nslPmD25D5g+cKSefCE=; b=OuAB+i2/Nei7RjUtinw6q3nM3m45NGwsgAZSc3PDm36LYJT1xu5zgQHFC9yUmlZRuQ 4nQWa1Wo4ot1vXQZxfq/kZTYpLVgQf+Dm1JLEnETkIw+DFDTBAYwUzjiNGVWVNHPYCQh b6mlRaKMLGUvY306pNZEHNZIVzRe9rs/cOYiq9/pcdLZ1i8fwLmgHVnGE7Aga/+oOp36 rprk9Yi7wFhOa2RRXloNe57fgDy7mcuuE57vTVP2ZS/QFT/J4zDD2c7D3KxsJYR3UxdN SXjdOhdwWIJv6hDoRwldMibKWWEQFPf7lOItpS8g1ntIgc0Am1ZICNSWNjf8Bt7Q8EtG owqw== X-Gm-Message-State: AOJu0YwOgFQkZPw7Hk2AJg5pLm424bpDd0FTIYaa0jdvrZWqoH3FKDAu VsiMgpRqIqxv/DDrnv/90Wfa+kTvwHz2XxXp2II= X-Google-Smtp-Source: AGHT+IG8fnudphfgdHldNvvN6b9HAIfRVnw9j+S5EodSB92Oy7omzXNzKjvaXZIc8FjPg6CYiCvZuPP1S4vu4R1ZY4M= X-Received: by 2002:adf:ed02:0:b0:31d:db2d:27c6 with SMTP id a2-20020adfed02000000b0031ddb2d27c6mr1286973wro.30.1695112797112; Tue, 19 Sep 2023 01:39:57 -0700 (PDT) Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20230911134650.200439213@linuxfoundation.org> <20230914085131.40974-1-gerhorst@amazon.de> <2023091653-peso-sprint-889d@gregkh> <2023091959-heroics-banister-7d6d@gregkh> In-Reply-To: <2023091959-heroics-banister-7d6d@gregkh> From: Alexei Starovoitov Date: Tue, 19 Sep 2023 01:39:44 -0700 Message-ID: Subject: Re: [PATCH 6.1 562/600] bpf: Fix issue in verifying allow_ptr_leaks To: Greg KH Cc: Daniel Borkmann , Luis Gerhorst , Alexei Starovoitov , Eddy Z , Yafang Shao , patches@lists.linux.dev, stable , Yonghong Song , Hagar Gamal Halim Hemdan , Puranjay Mohan , Luis Gerhorst Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, Sep 19, 2023 at 1:34=E2=80=AFAM Greg KH wrote: > > On Tue, Sep 19, 2023 at 08:26:28AM +0200, Daniel Borkmann wrote: > > On 9/16/23 1:35 PM, Greg KH wrote: > > > On Thu, Sep 14, 2023 at 08:51:32AM +0000, Luis Gerhorst wrote: > > > > > 6.1-stable review patch. If anyone has any objections, please le= t me know. > > > > > > > > > > From: Yafang Shao > > > > > > > > > > commit d75e30dddf73449bc2d10bb8e2f1a2c446bc67a2 upstream. > > > > > > > > I unfortunately have objections, they are pending discussion at [1]= . > > > > > > > > Same applies to the 6.4-stable review patch [2] and all other backp= orts. > > > > > > > > [1] https://lore.kernel.org/bpf/20230913122827.91591-1-gerhorst@ama= zon.de/ > > > > [2] https://lore.kernel.org/stable/20230911134709.834278248@linuxfo= undation.org/ > > > > > > As this is in the tree already, and in Linus's tree, I'll wait to see > > > if any changes are merged into Linus's tree for this before removing = it > > > from the stable trees. > > > > > > Let us know if there's a commit that resolves this and we will be gla= d > > > to queue that up. > > > > Commit d75e30dddf73 ("bpf: Fix issue in verifying allow_ptr_leaks") is = not > > stable material. It's not really a "fix", but it will simply make direc= t > > packet access available to applications without CAP_PERFMON - the latte= r > > was required so far given Spectre v1. However, there is ongoing discuss= ion [1] > > that potentially not much useful information can be leaked out and ther= efore > > lifting it may or may not be ok. If we queue this to stable and later f= igure > > we need to revert the whole thing again because someone managed to come= up > > with a PoC in the meantime, then there's higher risk of breakage. > > Ick, ok, so just this one commit should be reverted? Or any others as > well? I don't think revert is necessary. Just don't backport any further.