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 40A443FB06 for ; Tue, 19 Sep 2023 09:26:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 616FFC433C8; Tue, 19 Sep 2023 09:26:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695115564; bh=dIX7K4nq2k96aQ9nFRVRlz0BG7mlTcFR0KgMSO2smsc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eiIKkVYTmUZKgX4koOKCuQJnfkZHGD3BIvdIi+Rluo5Usjh8Kl++JxDPeevpXFU8v 16U4ED6+eSENcM6MjDSHA5fD1bIIRhNqUX7wWaFa3ELiAyT+sKG3mbzsBr1UIVzuUO FcgdK33Ezlw81DLyrs9+StgeZBBtXEDu/whmDw2w= Date: Tue, 19 Sep 2023 11:26:00 +0200 From: Greg KH To: Alexei Starovoitov 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 Subject: Re: [PATCH 6.1 562/600] bpf: Fix issue in verifying allow_ptr_leaks Message-ID: <2023091934-frequency-unloader-7cd7@gregkh> References: <20230911134650.200439213@linuxfoundation.org> <20230914085131.40974-1-gerhorst@amazon.de> <2023091653-peso-sprint-889d@gregkh> <2023091959-heroics-banister-7d6d@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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Sep 19, 2023 at 01:39:44AM -0700, Alexei Starovoitov wrote: > On Tue, Sep 19, 2023 at 1:34 AM 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 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? > > I don't think revert is necessary. Just don't backport any further. Ok, thanks, it's not backported into any other kernels at the moment, so I'll not worry about this anymore :) greg k-h