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 6885E1EA65 for ; Tue, 30 Sep 2025 02:06:24 +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=1759197984; cv=none; b=Xjgr8KRpPU6f0wAKZz7TSQuYQ/1WWMNAGqvzODf+Jrrqz8MxJddwlPcI8CFQM2+Ep+D7A9HkWaF01SKM7gYxBlgzHhTf4SI3lFgQelPLq99cGEs0J3MXjM10tjFhXJ3Gf2MRJKhVxzLXe+IFcrPhsofThpwM585EO4ZAlh3vTlM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759197984; c=relaxed/simple; bh=+TFC4uxivr+Kt82Mvgij3LA3e0HSes26wIQizUcLzCg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aM/W3dtDE+c8r7ipeLLbxdotczy4HemGXQ8bjuSGmIgl4sr5F8dviHHdVEjnoknrQgL7Cm+HISuVFpWR2r73BMHa+EEm6t+xp4GFU11CNntOw2qiWBLIKgYLcuKsLhHVwLibRWyp52j31hKrMvHmtXqrMhpVdaVK/zf67t9vQW8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DKSDeesr; 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="DKSDeesr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31A92C4CEF4; Tue, 30 Sep 2025 02:06:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759197984; bh=+TFC4uxivr+Kt82Mvgij3LA3e0HSes26wIQizUcLzCg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DKSDeesr8shtE5rQLLWmFl6PMDTyklIkKYRIFUL2hXf5JrDGZByELyYQ3c/pCoebW zmwoXdQJsGCZE7jHhm4qk46YSIj/o8SLkj9+SI0UwlCYxtUDgS169RkdgFq0/NtGht IJt0w3wY4S66z2nxEZXVKicHkhmjrlZhfDg/1OAgVJ2+JpZp9Fmr+Tbfe2kHZWXP8f unwodPviOC9lNcC/fZfqpBstllpCH9NkCZlxJA1F1pSrgZj9G8BLH1KgCwoyEYMjYT ygksthx/1wvf7DP4oxq7/MaaB3wd24tsysn0BiFVtySOdz1+HXrQ1lEwxaOOT2UFMm k3vAjOLruqohw== Date: Mon, 29 Sep 2025 19:06:23 -0700 From: Kees Cook To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Andy Shevchenko , Christopher Fore , "Gustavo A. R. Silva" , Junjie Cao , Lad Prabhakar , Linus Walleij , Nathan Chancellor , Philipp Zabel , Vegard Nossum Subject: Re: [GIT PULL] hardening updates for v6.18-rc1 Message-ID: <202509291904.479E322AE9@keescook> References: <202509291213.E313986EE@keescook> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Sep 29, 2025 at 05:59:17PM -0700, Linus Torvalds wrote: > On Mon, 29 Sept 2025 at 12:15, Kees Cook wrote: > > > > Please pull these hardening updates for v6.18-rc1. One notable addition > > is the creation of the "transitional" keyword for kconfig so CONFIG > > renaming can go more smoothly. This has been a long-standing deficiency, > > and with the renaming of CONFIG_CFI_CLANG to CONFIG_CFI (since GCC will > > soon have KCFI support), this came up again. The breadth of the diffstat > > is mainly this renaming. > > So I really like this addition conceptually, but it doesn't actually > seem to work. > > My clang-building tree config had > > CONFIG_ARCH_SUPPORTS_CFI_CLANG=y > # CONFIG_CFI_CLANG is not set > CONFIG_HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG=y > > but then when I pulled this and did a "make oldconfig" I get Kconfig asking me > > Use Kernel Control Flow Integrity (kCFI) (CFI) [N/y/?] (NEW) > > anyway, in order to get > > CONFIG_ARCH_SUPPORTS_CFI=y > # CONFIG_CFI is not set > CONFIG_HAVE_CFI_ICALL_NORMALIZE_INTEGERS=y > > and I thought the whole point was that it would recognize the old > Kconfig names and transition them to the new ones. And it very clearly > does not. > > So I'm a bit disappointed. Possibly because I expected the > "transitional" keyword to be doing more than it does. But possibly > because it's buggy and doesn't actually do what it is *supposed* to > do. Ah, the existing "=n" didn't persist. That's not expected. I will take a look. -- Kees Cook