From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793201854; b=AdzpMF/8tDJjoLjzM21fDALqQ1z+aa1JocmP+7R0kuDtd2tk37JKsl/mJhH8dav2/lKA e1hqB39RHOUi+MErgmiPU9bpvWQs4bWntlsotI+ZrXIqyhCoPd7w6RLWo1lpS/4rjYwT3 u5MqQ1UzOVK7dK32BgJdI7I7cTXdDIPiMpKy7ez4ZLk15NN0k7V1DpNh89yGE3wAhdDkO ElhUqsx1FxB1AwRo9fkYZFahG0KhK0F9rq88s0N4XKRhzagAvixl8U5I2uF8ukFkh7OUR jPyvbYFda01UvPn3Yk+Ek5NwB6A0In6RDaxtRjjM7W4wDHvVyI40i9ncwE7MNHmgpOA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793201854; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=iEstB2Yqj/OV4/iylOODgI3e0ZEYrocagDRh/bGqrzU=; b=p5eh0pF7e5u2CB/8b99RJf81Ev1H5IUCqMEwRG8hkb/PU2VmGE9/REZadRCsOHSBOYgJ MzA0v8oy/+nZ/Mv27irmlx0mzWqTYrEwLTg6RPFEl1Q2UY9saTiTaQNE81g+wArfMZI8H E9lUBV0VvOrNiUDd6Sj9qzJL7dVy6tlTHGQkUQW39MwSRQj8xzrkYDXQD0PTNrIZTSQ8z BbLPJ+Pm4FUqIbpLBe97Sd5iQk8neCV2/xNrK4BocOkWd2SIh8A7pEKKdwwcrIcykblXG jqafWlU3mWOP1s3xjgg2WbV1nx8+7puuN1yKKoS3tkrTQKDcLEZV9A+cwACP8i6I5Iw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=geYSyUoQ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B64D606A32A; Wed, 28 Oct 2026 15:37:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=geYSyUoQ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B7081F031E2; Wed, 28 Oct 2026 15:37:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793201853; bh=iEstB2Yqj/OV4/iylOODgI3e0ZEYrocagDRh/bGqrzU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=geYSyUoQgrGtwDbkkBwlXHTFNbhkeqzSW52AV3xgPmMnYLfnuh7bWTDf/yXqU3F0/ Uwp1PErTxxkS8aF8yIsAFIQ1nhA00DgrpkkCC7FiIsrXMH53H1wB36EDCWCPl02axG 28tMyiaQfMjN4uVROLQPgjZg0X5RcvRFC6U0tFe9mplLI5iAzo3pSuq09urihZoG+s NJw+Uih0fQ4fiBUQjBo9hNO6n41sCFUDB0nkmyrg9XfpgJxgSuXj5uT4keq74WaL8W xjG6EiPDB4+X8HzbnjU3aigdSmQzXkr3BZpA2vajjR8JZDNm0nzmY1+LNovKF3Zw4F DGM3/VWtbmnHg== Date: Wed, 28 Oct 2026 15:37:31 +0000 From: Harry Yoo To: Chris Down Cc: Vlastimil Babka , Andrew Morton , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Kees Cook , Marco Elver , GONG Ruiqi , Jan Kiszka , Kieran Bingham , Jonathan Corbet , linux-mm@kvack.org, linux-hardening@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH 0/8] mm/slab: Support selecting slab hardening features at boot Message-ID: References: X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Oct 28, 2026 at 11:27:37PM +0800, Chris Down wrote: > Hi Harry, > > Harry Yoo writes: > > If we end up supporting boot-time parameters for hardening, > > I think it should be all enabled (or disabled) by: > > > > slab_hardening=none|light|full > > # please feel free to suggest bertter names > > > > none: "Turn of all of them to maximize performance" > > > > light: "I'm willying to sacrifice _some_ memory and CPU for security" > > > > full: "I'm willying to sacrifice more overhead for security > > > > IMHO more fine-grained knob for each feature doesn't make much sense. > > I think if we did the 4 knobs that is a good idea. Given now it's two, I > think it seems reasonable to keep it as two separate knobs unless you > object? Otherwise I think given it will only cover the latter two, it > should be something like kmalloc_isolation= instead. Let me know what you > think. There has been constant, steady efforts to add more and more hardening features over the last decade. So I'd say slab_hardening= is more future proof :-) Kees or Marco might have more insights on this. -- Cheers, Harry / Hyeonggon