From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A3F96F509 for ; Tue, 19 Sep 2023 08:34:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A285C433C9; Tue, 19 Sep 2023 08:34:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695112495; bh=QpajV1PeBnPAdnf7ameyYmcl97VZ+w2I1GuQpWvpu+k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TbQEm7sAyxi23fp31KLGDy/VfAIdYAEGn5ivqlSZI3bVaj56YgIo5aEFXc+sFbFQE ll4nZ2/n2jrmYFRyCGX1Lqw6ddReV5HptWa9FmyuVVMuu84PcmAosWDmd4fu2vHDdq 6PPDmdjWk0cS7luFAc15cskcM4PTkUtpsXkjtH2A= Date: Tue, 19 Sep 2023 10:32:16 +0200 From: Greg KH To: Daniel Borkmann Cc: gerhorst@cs.fau.de, alexei.starovoitov@gmail.com, ast@kernel.org, eddyz87@gmail.com, laoar.shao@gmail.com, patches@lists.linux.dev, stable@vger.kernel.org, yonghong.song@linux.dev, hagarhem@amazon.de, puranjay12@gmail.com, Luis Gerhorst Subject: Re: [PATCH 6.1 562/600] bpf: Fix issue in verifying allow_ptr_leaks Message-ID: <2023091959-heroics-banister-7d6d@gregkh> References: <20230911134650.200439213@linuxfoundation.org> <20230914085131.40974-1-gerhorst@amazon.de> <2023091653-peso-sprint-889d@gregkh> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 let 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 backports. > > > > > > [1] https://lore.kernel.org/bpf/20230913122827.91591-1-gerhorst@amazon.de/ > > > [2] https://lore.kernel.org/stable/20230911134709.834278248@linuxfoundation.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 glad > > 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 direct > packet access available to applications without CAP_PERFMON - the latter > was required so far given Spectre v1. However, there is ongoing discussion [1] > that potentially not much useful information can be leaked out and therefore > lifting it may or may not be ok. If we queue this to stable and later figure > 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? thanks, greg k-h