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 C52496BFCE; Wed, 7 Feb 2024 22:12:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707343964; cv=none; b=qs1q7Id6uWmhPeIJl/U/CHzqGw6GZebceW89TTUxOBoGE41HJcGZbCH2ZUcWIi3zorV6iE7TUfEu8mjCVTfMkFhwfxE4r5JiBYrGAyLbhtCux6qVMjHM+aG6jzd1cn/iM/BRTEzDowqZcFhc4ln4Nmow8GAOT2lj5iU87hyFPhY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707343964; c=relaxed/simple; bh=YUwb9LPhByrA5rHlYzP6QyFWe353UDXpzQHTrHwvmsg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qC2/AUHLo8McMgygk2lQ5hV7EAiHVrK8mPBCbiomnMCSot9bpWNNmaj5W29vZSyrQwrsxEaPLglF+YVQc7ka11DTZhaZWuJZC72CDb7nsUi43a3QXRAnRgZo20dCVZbSFNrVconLtCMrAbwfSNMh1bfrReTl/xaOA2yziKrWQ9E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kfCOSaGP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kfCOSaGP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A3B9C433F1; Wed, 7 Feb 2024 22:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707343964; bh=YUwb9LPhByrA5rHlYzP6QyFWe353UDXpzQHTrHwvmsg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=kfCOSaGPlIPrjeGjTjlWPLA3Ee1P/v5pMNFoAsmMuDFscDEHL8oLLwoqVgZdBsNZm g0IfsSgIygSWbfJt23h28pCfvHmgU4fFbBUcLJlzEqwY4WM+gRC21dWcRnYWMqBXqL aEFJNYKfa/Iasi8IJT9FHOzaZdfvnXPRRdmWVbAAkwVTgdwy/dq4cQnKa+XMRO8gZS vLZdk8r786+00JCRWU9RyJ3dZm2+HgGR0JpOdD9h/oozE/oNprJEl4Im6M7ZabZzyW dI+w/3yG7Gf59wrrE2sOTk53sJEdTcJhOYOPbSIm3g3iQLpUuiOwqaNLY+xggsJ1vT 54Rozk+LSJDgQ== Message-ID: <7a3d2c33-74ce-45fb-bddc-9eceb6dd928b@kernel.org> Date: Wed, 7 Feb 2024 23:12:38 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: KFENCE: included in x86 defconfig? Content-Language: en-GB, fr-BE To: Borislav Petkov Cc: Marco Elver , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, Netdev , Jakub Kicinski , linux-hardening@vger.kernel.org, Kees Cook , the arch/x86 maintainers References: <20240207181619.GDZcPI87_Bq0Z3ozUn@fat_crate.local> <20240207190444.GFZcPUTAnZb_aSlSjV@fat_crate.local> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: <20240207190444.GFZcPUTAnZb_aSlSjV@fat_crate.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 07/02/2024 20:04, Borislav Petkov wrote: > On Wed, Feb 07, 2024 at 07:35:53PM +0100, Matthieu Baerts wrote: >> Sorry, I'm sure I understand your suggestion: do you mean not including >> KFENCE in hardening.config either, but in another one? >> >> For the networking tests, we are already merging .config files, e.g. the >> debug.config one. We are not pushing to have KFENCE in x86 defconfig, it >> can be elsewhere, and we don't mind merging other .config files if they >> are maintained. > > Well, depends on where should KFENCE be enabled? Do you want people to > run their tests with it too, or only the networking tests? If so, then > hardening.config probably makes sense. > > Judging by what Documentation/dev-tools/kfence.rst says: > > "KFENCE is designed to be enabled in production kernels, and has near zero > performance overhead." > > this reads like it should be enabled *everywhere* - not only in some > hardening config. > > But then again I've never played with it so I don't really know. > > If only the networking tests should enable it, then it should be a local > .config snippet which is not part of the kernel. > > Makes more sense? Yes, thank you! On my side, KFENCE is currently in local .config snippet, not part of the kernel. If it has near zero performance overhead and can be used in productions kernel, maybe it can be set elsewhere to be used by more people? But not everywhere, according to Marco. Cheers, Matt -- Sponsored by the NGI0 Core fund.