From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 31C082571C2 for ; Thu, 10 Apr 2025 09:54:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744278892; cv=none; b=pIW3a6A1VTPxB0GUUQWvd6BGiOYFcMEwMffxPvuOR8fqRRcfIhkU82ALAqrNiZWiwcR4552bNtFG6HdylpwytPvsuxX67yZ8UlCd7av1g3cO7UayCEiiVMPI8Nxbh9lKeYHn1Os8gs6gNWDW+9nt0HPjlE/xJ/tcmPUh+l2VrNM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744278892; c=relaxed/simple; bh=e8pssY7zMOIxbmYX6eTCFTk3ZdlqMN7WT1Tmj47w+Bk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bdusTZZCm6KtU+jU7hBx7oHsXs7KcoQrCfePKdXwXI2zdg3/V6QwgrQ7aoP/VX04hvVbvqdzEeAK3V4A+kDjXdGsBBbF0PFSJ2+XkgHc9ru+8CZELHMgImnKVQAJ2L+vAikOnKV9yOrqyDuxNJ3t9uDFacQe28o3u6FHgRiURWM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=d15o3W+s; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="d15o3W+s" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744278890; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=FBjnDHe05jMrdyAmjlXqvilcIE/JjsVNiTKFB4wAT6A=; b=d15o3W+stNsYKXs++4sdstjmcASii/Wg3R1UVLE8qYjA/DKiA5K9z/L+m+gRqvvnGXW+oc ZTcjd+7EED8rXwZTxjVhmowgrsn3klwyIwOyALuUAd1RcGyI2GC8cTX2uMouuug6KKLimc xcVx5ArTaXK09CDgB/bBdrQ7DfFpFiI= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-80-IMCN5vjAMv-jci4TsADYlw-1; Thu, 10 Apr 2025 05:54:44 -0400 X-MC-Unique: IMCN5vjAMv-jci4TsADYlw-1 X-Mimecast-MFC-AGG-ID: IMCN5vjAMv-jci4TsADYlw_1744278882 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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 mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2C7A1180AF53; Thu, 10 Apr 2025 09:54:41 +0000 (UTC) Received: from localhost (unknown [10.72.112.38]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 848791828AA5; Thu, 10 Apr 2025 09:54:38 +0000 (UTC) Date: Thu, 10 Apr 2025 17:54:33 +0800 From: Baoquan He To: steven chen Cc: zohar@linux.ibm.com, 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, madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@hansenpartnership.com, vgoyal@redhat.com, dyoung@redhat.com Subject: Re: [PATCH v11 8/9] ima: make the kexec extra memory configurable Message-ID: References: <20250402124725.5601-1-chenste@linux.microsoft.com> <20250402124725.5601-9-chenste@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-integrity@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: <20250402124725.5601-9-chenste@linux.microsoft.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 04/02/25 at 05:47am, steven chen wrote: > The extra memory allocated for carrying the IMA measurement list across > kexec is hard-coded as half a PAGE. Make it configurable. > > Define a Kconfig option, IMA_KEXEC_EXTRA_MEMORY_KB, to configure the > extra memory (in kb) to be allocated for IMA measurements added during > kexec soft reboot. Ensure the default value of the option is set such > that extra half a page of memory for additional measurements is allocated > for the additional measurements. > > Update ima_add_kexec_buffer() function to allocate memory based on the > Kconfig option value, rather than the currently hard-coded one. > > Suggested-by: Stefan Berger > Signed-off-by: Tushar Sugandhi > Signed-off-by: steven chen > Reviewed-by: Stefan Berger > Reviewed-by: Mimi Zohar > --- > security/integrity/ima/Kconfig | 10 ++++++++++ > security/integrity/ima/ima_kexec.c | 16 +++++++++++----- > 2 files changed, 21 insertions(+), 5 deletions(-) > > diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig > index 475c32615006..d73c96c3c1c9 100644 > --- a/security/integrity/ima/Kconfig > +++ b/security/integrity/ima/Kconfig > @@ -321,4 +321,14 @@ config IMA_DISABLE_HTABLE > help > This option disables htable to allow measurement of duplicate records. > > +config IMA_KEXEC_EXTRA_MEMORY_KB > + int "Extra memory for IMA measurements added during kexec soft reboot" > + depends on IMA_KEXEC > + default 0 Usually a new Kconfig item which accepts a range should define the range boundary, otherwise it's not clear to people how large or how small it can be set. For example, can I set it as value of 1<<40? We should at least estimate a possible upper limit for it for other people's reference. My personal opinion. The rest looks good to me. > + help > + IMA_KEXEC_EXTRA_MEMORY_KB determines the extra memory to be > + allocated (in kb) for IMA measurements added during kexec soft reboot. > + If set to the default value of 0, an extra half page of memory for those > + additional measurements will be allocated. > + > endif ...snip...