From patchwork Thu Jan 21 17:30:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 12037249 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F0F2C433E9 for ; Thu, 21 Jan 2021 17:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09CD722527 for ; Thu, 21 Jan 2021 17:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388618AbhAURbJ (ORCPT ); Thu, 21 Jan 2021 12:31:09 -0500 Received: from linux.microsoft.com ([13.77.154.182]:57656 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388593AbhAURat (ORCPT ); Thu, 21 Jan 2021 12:30:49 -0500 Received: from localhost.localdomain (c-73-42-176-67.hsd1.wa.comcast.net [73.42.176.67]) by linux.microsoft.com (Postfix) with ESMTPSA id 0502320B6C40; Thu, 21 Jan 2021 09:30:09 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 0502320B6C40 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1611250209; bh=n1S4TbdTz/yn+EbNkKnNYjNg0Ij/jNTpwezyFWx+1Wk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eAsCtlFB0Ga2tjsVs2efUQkBP05ADsVa3PFbpGHO6NxCZ9d+aeud6uOEVSBOeM0yy wlgMATBedMKfgED6W2A9Hn2fuFadHgOjsAdLQqdOQsLGx7l4nAUhK7+tSUsXFhyfUV Lqd/AjcKAYmtv/LX0PWPrEw3WUq+ulrfRj7UrN8w= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, bauerman@linux.ibm.com, dmitry.kasatkin@gmail.com, ebiederm@xmission.com, gregkh@linuxfoundation.org, sashal@kernel.org, tyhicks@linux.microsoft.com Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 2/2] ima: Free IMA measurement buffer after kexec syscall Date: Thu, 21 Jan 2021 09:30:03 -0800 Message-Id: <20210121173003.18324-2-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210121173003.18324-1-nramas@linux.microsoft.com> References: <20210121173003.18324-1-nramas@linux.microsoft.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org IMA allocates kernel virtual memory to carry forward the measurement list, from the current kernel to the next kernel on kexec system call, in ima_add_kexec_buffer() function. This buffer is not freed before completing the kexec system call resulting in memory leak. Add ima_buffer field in "struct kimage" to store the virtual address of the buffer allocated for the IMA measurement list. Free the memory allocated for the IMA measurement list in kimage_file_post_load_cleanup() function. Signed-off-by: Lakshmi Ramasubramanian Suggested-by: Tyler Hicks Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Reviewed-by: Tyler Hicks Reviewed-by: Thiago Jung Bauermann --- include/linux/kexec.h | 5 +++++ kernel/kexec_file.c | 5 +++++ security/integrity/ima/ima_kexec.c | 2 ++ 3 files changed, 12 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 9e93bef52968..5f61389f5f36 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -300,6 +300,11 @@ struct kimage { /* Information for loading purgatory */ struct purgatory_info purgatory_info; #endif + +#ifdef CONFIG_IMA_KEXEC + /* Virtual address of IMA measurement buffer for kexec syscall */ + void *ima_buffer; +#endif }; /* kexec interface functions */ diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index b02086d70492..5c3447cf7ad5 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -166,6 +166,11 @@ void kimage_file_post_load_cleanup(struct kimage *image) vfree(pi->sechdrs); pi->sechdrs = NULL; +#ifdef CONFIG_IMA_KEXEC + vfree(image->ima_buffer); + image->ima_buffer = NULL; +#endif /* CONFIG_IMA_KEXEC */ + /* See if architecture has anything to cleanup post load */ arch_kimage_file_post_load_cleanup(image); diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 212145008a01..8eadd0674629 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -130,6 +130,8 @@ void ima_add_kexec_buffer(struct kimage *image) return; } + image->ima_buffer = kexec_buffer; + pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n", kbuf.mem); }