From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lamorak.hansenpartnership.com (lamorak.hansenpartnership.com [198.37.111.173]) (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 363E91DF75C; Sat, 11 Oct 2025 17:09:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.37.111.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760202587; cv=none; b=ONyHcCtawN/jBdyRE4APkYXG2NiInXrgvwGfh0aFZxbmyWEQ6bMEmK8b+2nZUZyWVbDkAr5+QMhKvjBmeGQy7eet3Njzby1KyiR8rL7+njhFUouSu9jJNmav+qOhs0ltA0ZkIfBsQ5BFJwKfZ0sCjk05nOmWUNvUbfGwcjnvVbo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760202587; c=relaxed/simple; bh=fOe3y2X0pagsg9/YZTVvaYkj97iuw6qruUWgqFKp9rc=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=MjofPkdRlm+jREQLZUSVFF0jwVaEJnr6o+xVaCpucdaGYUXp2FtJKX/5J/0zqYzfTCE53w/jnAj3vpOg4S3NCTMG2F1ulC3/sSMVrAG0Ty+KpvgIw2pnd+5Y+JsU/eiKLwVifPix/PGCKoVGUge16JgsS+g+hNFXU+N1VNb3z/k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=MovhBlEB; arc=none smtp.client-ip=198.37.111.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="MovhBlEB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1760202584; bh=fOe3y2X0pagsg9/YZTVvaYkj97iuw6qruUWgqFKp9rc=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=MovhBlEBvIndlukPbA192D37DEXXtoT6NlKLoMhxHVbxCxuehdI52m7Ll5ua4KIXr yjBP/Fxfjh4cTTCoqYkOK+9VjkBmN57BxZP+C3N+TX1uVsgObIws1FYTPLwJ9tV064 Rrwen8jM+VF89owEM5tyDlW0OJnv3gwqgOsZYOJg= Received: from lingrow.int.hansenpartnership.com (unknown [IPv6:2601:5c4:4302:c21::a774]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lamorak.hansenpartnership.com (Postfix) with ESMTPSA id 8F0801C0014; Sat, 11 Oct 2025 13:09:43 -0400 (EDT) Message-ID: Subject: Re: [PATCH bpf-next v2 0/3] BPF signature hash chains From: James Bottomley To: Alexei Starovoitov Cc: Paul Moore , Alexei Starovoitov , KP Singh , Linus Torvalds , Blaise Boscaccy , bpf , LSM List , "K. Y. Srinivasan" , Daniel Borkmann , Andrii Nakryiko , wufan@linux.microsoft.com, Quentin Monnet Date: Sat, 11 Oct 2025 13:09:42 -0400 In-Reply-To: References: <20250929213520.1821223-1-bboscaccy@linux.microsoft.com> <88703f00d5b7a779728451008626efa45e42db3d.camel@HansenPartnership.com> <42bc677e031ed3df4f379cd3d6c9b3e1e8fadd87.camel@HansenPartnership.com> Autocrypt: addr=James.Bottomley@HansenPartnership.com; prefer-encrypt=mutual; keydata=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MAdnPcDVFzaXJdlAAJdjfg/lyJtAyxifflG8NnXJ3elwGqoBso84XBNWWzbc5VKmatzhYLOvXtfzDhu4mNPv/z7S1HTtRguI0NlH5RVBzSvfzybin9hysE3/+r3C0HJ2xiOHzucNAmG03aztzZYDMTbKQW4bQqeD5MJxT68vBYu8MtzfIe41lSLpb/qlwq1qg0iQElBBgBAgAPBQJUdhaZAhsMBQkA7U4AAAoJEIFK5HwhSFTW3YgH/AyJL2rlCvGrkLcas94ND9Pmn0cUlVrPl7wVGcIV+6I4nrw6u49TyqNMmsYam2YpjervJGgbvIbMzoHFCREi6R9XyUsw5w7GCRoWegw2blZYi5A52xe500+/RruG//MKfOtVUotu3N+u7FcXaYAg9gbYeGNZCV70vI+cnFgq0AEJRdjidzfCWVKPjafTo7jHeFxX7Q22kUfWOkMzzhoDbFg0jPhVYNiEXpNyXCwirzvKA7bvFwZPlRkbfihaiXDE7QKIUtQ10i5kw4C9rqDKwx8F0PaWDRF9gGaKd7/IJGHJaac/OcSJ36zxgkNgLsVX5GUroJ2GaZcR7W9Vppj5H+C4UgRkuRyTEwgqhkjOPQMBBwIDBOySomnsW2SkApXv1zUBaD38dFEj0LQeDEMdSE7bm1fnrdjAYt0f/CtbUUiDaPodQk2qeHzOP6wA/2K6rrjwNIWJAT0EGAEIACcDGyAEFiEE1WBuc8i0YnG+rZrfgUrkfCFIVNYFAmWoM/gFCQSxfmUACgkQgUrkfCFIVNZhTgf/VQxtQ5rgu2aoXh2KOH6naGzPKDkYDJ/K7XCJAq3nJYEpYN8G+F8mL/ql0hrihAsHfjmoDOlt+INa3AcG3v0jDZIMEzmcjAlu7g5NcXS3kntcMHgw3dCgE9eYDaKGipUCubdXvBaZWU6AUlTldaB8FE6u7It7+UO+IW4/L+KpLYKs8V5POInu2rqahlm7vgxY5iv4Txz4EvCW2e4dAlG 8mT2Eh9SkH+YVOmaKsajgZgrBxA7fWmGoxXswEVxJIFj3vW7yNc0C5HaUdYa5iGOMs4kg2ht4s7yy7NRQuh7BifWjo6BQ6k4S1H+6axZucxhSV1L6zN9d+lr3Xo/vy1unzA== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.3 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Sat, 2025-10-11 at 09:31 -0700, Alexei Starovoitov wrote: > On Sat, Oct 11, 2025 at 7:52=E2=80=AFAM James Bottomley > wrote: > >=20 > > It doesn't need to, once we check both the loader and the map, the > > integrity is verified and the loader can be trusted to run and > > relocate the map into the bpf program >=20 > You should read KP's cover letter again and then research trusted > hash chains. Here is a quote from the first googled link: >=20 > "A trusted hash chain is a cryptographic process used to verify the > integrity and authenticity of data by creating a sequence of hash > values, where each hash is linked to the next". >=20 > In addition KP's algorithm was vetted by various security teams. > There is nothing novel here. It's a classic algorithm used > to verify integrity and that's what was implemented. Both KP and Blaise's patch sets are implementations of trusted hash chains. The security argument isn't about whether the hash chain algorithm works, it's about where, in relation to the LSM hook, the hash chain verification completes. Regards, James