From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zztop.nucleusys.com (lan.nucleusys.com [92.247.61.126]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3s5M0c0xPtzDqQ1 for ; Fri, 5 Aug 2016 19:27:44 +1000 (AEST) Date: Fri, 5 Aug 2016 11:44:25 +0300 From: Petko Manolov To: Mimi Zohar Cc: linux-security-module@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, Dave Young , kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Thiago Jung Bauermann Subject: Re: [PATCH 1/7] ima: on soft reboot, restore the measurement list Message-ID: <20160805084425.GA7572@localhost> References: <1470313475-20090-1-git-send-email-zohar@linux.vnet.ibm.com> <1470313475-20090-2-git-send-email-zohar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1470313475-20090-2-git-send-email-zohar@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 16-08-04 08:24:29, Mimi Zohar wrote: > The TPM PCRs are only reset on a hard reboot. In order to validate a > TPM's quote after a soft reboot (eg. kexec -e), the IMA measurement list > of the running kernel must be saved and restored on boot. This patch > restores the measurement list. > > Changelog: > - call ima_load_kexec_buffer() (Thiago) > > Signed-off-by: Mimi Zohar > --- > security/integrity/ima/Makefile | 1 + > security/integrity/ima/ima.h | 10 ++ > security/integrity/ima/ima_init.c | 2 + > security/integrity/ima/ima_kexec.c | 55 +++++++++++ > security/integrity/ima/ima_queue.c | 10 ++ > security/integrity/ima/ima_template.c | 171 ++++++++++++++++++++++++++++++++++ > 6 files changed, 249 insertions(+) > create mode 100644 security/integrity/ima/ima_kexec.c > > diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile > index c34599f..c0ce7b1 100644 > --- a/security/integrity/ima/Makefile > +++ b/security/integrity/ima/Makefile > @@ -8,4 +8,5 @@ obj-$(CONFIG_IMA) += ima.o > ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ > ima_policy.o ima_template.o ima_template_lib.o ima_buffer.o > ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o > +ima-$(CONFIG_KEXEC_FILE) += ima_kexec.o > obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > index b5728da..84e8d36 100644 > --- a/security/integrity/ima/ima.h > +++ b/security/integrity/ima/ima.h > @@ -102,6 +102,13 @@ struct ima_queue_entry { > }; > extern struct list_head ima_measurements; /* list of all measurements */ > > +/* Some details preceding the binary serialized measurement list */ > +struct ima_kexec_hdr { > + unsigned short version; > + unsigned long buffer_size; > + unsigned long count; > +} __packed; Unless there is no real need for this structure to be packed i suggest dropping the attribute. When referenced through pointer 32bit ARM and MIPS (and likely all other 32bit RISC CPUs) use rather inefficient byte loads and stores. Worse, if, for example, ->count is going to be read/written concurrently from multiple threads we get torn loads/stores thus losing atomicity of the access. Petko