From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 174A3281369; Thu, 10 Apr 2025 14:15:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744294559; cv=none; b=Y1cFNcnOeNSWX9LMbykr2W6hLAZYTgQdrUbllr11hy9gH5o34Wu4b/FdNGbUqdkrOuY1DNW09c1H4tFzFf8Ke77uIQmcl5fdrr5wmrt4JV/clMrRZROSbL14C4UxZ3203U4PavjDDNHHeNmE4AXP07VlhdOtA2lMvSpuB3j952s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744294559; c=relaxed/simple; bh=LEbTWlzpaihB6IQHTlbaA5Ot/ypsjb5J6qcme4C6YZE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pCMv71okVNUtXYK1cgajqCIt61UubtQFwOThimM5kT3hzXWMmelJ58wHeSoZJoNIb1Pn6zF2D0it1SVNnBUH+G6RrS9AkH5JFSE0rtfpOo81mJw11onGorbqZePioDro2y1I+70BARPL12xG018kSMc9NYGj0mBJ9weEIjvuCYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=n7LJlLUT; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="n7LJlLUT" Received: from [100.70.200.180] (unknown [172.200.70.13]) by linux.microsoft.com (Postfix) with ESMTPSA id 680852113E88; Thu, 10 Apr 2025 07:15:54 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 680852113E88 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744294556; bh=XmfJAaDZRcuR0IspL/CV2qpL+dgL7BxJ5z1ZXihUDxU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=n7LJlLUTIHoUKqUDPHHPpZzH1WJi5CQ8KlXno+uTZvwvdN8pM4Z+WPo2tZqF/BKwG 0ktcd7KAKLp+gQVRrUeYUhJAPVHUk0l+0DtBVoLoHkF3BF8hLT8JYqFQ3Yui4nCDQg sKieQ7MXh4X0Af+AcESsv9OuyreI5id5K4RRqudY= Message-ID: <98c63e22-b9f7-40b9-90d0-aa67534f9107@linux.microsoft.com> Date: Thu, 10 Apr 2025 07:15:52 -0700 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 6/9] ima: kexec: move IMA log copy from kexec load to execute To: Mimi Zohar , stefanb@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, ebiederm@xmission.com, paul@paul-moore.com, code@tyhicks.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Cc: madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@HansenPartnership.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com References: <20250402124725.5601-1-chenste@linux.microsoft.com> <20250402124725.5601-7-chenste@linux.microsoft.com> <96ae5a8efbcb894e096881f1dd7a4939ce0a9490.camel@linux.ibm.com> Content-Language: en-US From: steven chen In-Reply-To: <96ae5a8efbcb894e096881f1dd7a4939ce0a9490.camel@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 4/8/2025 9:17 AM, Mimi Zohar wrote: > On Wed, 2025-04-02 at 05:47 -0700, steven chen wrote: >> ima_dump_measurement_list() is called during kexec 'load', which may >> result in loss of IMA measurements during kexec soft reboot. Due to >> missed measurements that only occurred after kexec 'load', this function >> needs to be called during kexec 'execute'. > Re-use the motivation from 5/9 (with tweak): > > The IMA log is currently copied to the new kernel during kexec 'load' using > ima_dump_measurement_list(). However, the IMA measurement list copied at kexec > 'load' may result in loss of IMA measurements records that only occurred after > the kexec 'load'. > > And finish the paragraph with: > Move the IMA measurement list log copy from kexec 'load' to 'execute'. > >> Make the kexec_segment_size variable a local static variable within the >> file, so it can be accessed during both kexec 'load' and 'execute'. >> >> Implement the kexec_post_load() function to be invoked after the new kernel >> image has been loaded for kexec. Instead of calling machine_kexec_post_load() >> directly from the kexec_file_load() syscall, call kexec_post_load(), which in >> turn calls machine_kexec_post_load() to maintain the original image processing. > Define kexec_post_load() as a wrapper for calling ima_kexec_post_load() and > machine_kexec_post_load(). Replace the existing direct call to > machine_kexec_post_load() with kexec_post_load(). > >> >> Invoke ima_kexec_post_load() within the kexec_post_load() API only for kexec >> soft reboot scenarios, excluding KEXEC_FILE_ON_CRASH. > "Don't call ima_kexec_post_load() on KEXEC_FILE_ON_CRASH" would be listed in the > Changelog if it changed, not here in the patch description. Please remove. > >> >> Register a reboot notifier for the ima_update_kexec_buffer() API within >> ima_kexec_post_load() to ensure it is called upon receiving a reboot >> notification. > Registering the reboot notifier was done in "[PATCH v11 5/9] ima: kexec: define > functions to copy IMA log at soft boot", not here. Please remove. > >> >> Move the ima_dump_measurement_list() call from ima_add_kexec_buffer() to >> ima_update_kexec_buffer() to copy the IMA log at the kexec 'execute' stage. > This information was already stated in the first paragraph as part of the > motivation for the patch. Please remove. > >> >> When there is insufficient memory to copy all the measurement logs, copy as >> much of the measurement list as possible. > Is this comment still applicable to this patch? > > Please review your patch descriptions before posting, making sure that > everything is still applicable. > > thanks, > > Mimi Hi Mimi, Thanks for your comments. I will update in next version. Steven >> Signed-off-by: Tushar Sugandhi >> Cc: Eric Biederman >> Cc: Baoquan He >> Cc: Vivek Goyal >> Cc: Dave Young >> Signed-off-by: steven chen >> Reviewed-by: Stefan Berger