From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1CE80C02198 for ; Mon, 3 Feb 2025 19:00:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KbbzVWtcOJ7Gt1QLNcb0WLEL7b64gQxfibl1JZ8EMTM=; b=0gDd/lW6zMcRJhLl+VaCIqyHuj SjZ4gy8nRpX9dw39vmJk6GgX1UMKQTcddr57JTllqFBG2qdgoV2+BCr0zpEl25GwcsIKW7t7mPOIY 7HBDLRkgTVHCiu5xVOyb2xlRcpA9tl3gOiTXorm3YFnrmG6iBvCxFEGebN/nUO4QIUs5KrojVEmhu Kvc1HioZt/8hAgyV81ZXH46z8y6BiJE92TgTNo5XWmEm5NUYGKI0UcR8wiNAiga4lusbFQQGnjVJp KNx2QEugWTYPRHYYSMvmnqoQGuyOnfkotvQHc3dmasw5/BOQvTKzwpta5+J7xLtqdrwvFcRqjy8RI kf4OdYXg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tf1g8-0000000GMWb-0Wm4; Mon, 03 Feb 2025 19:00:16 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tf1PX-0000000GIp1-0kF8 for kexec@lists.infradead.org; Mon, 03 Feb 2025 18:43:08 +0000 Received: from localhost.localdomain (unknown [167.220.59.4]) by linux.microsoft.com (Postfix) with ESMTPSA id 09A19205493C; Mon, 3 Feb 2025 10:43:05 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 09A19205493C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1738608185; bh=KbbzVWtcOJ7Gt1QLNcb0WLEL7b64gQxfibl1JZ8EMTM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bNj80hcAhiATBlbzHimaIioftHHv3CwJh7ZMwrB+kcXp6Oy2x/dt0hf/677kesmU2 NnHosZZl8RgyT32j/3taEM3mkTC11LVrBx+2fz8IRL3fDTzf3oVkTYrfZQT6xHxQQw 0/rWVXvWmkNUtTEvZWc/q5tt2g8wyQtcgw8p/uiM= From: steven chen To: 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, inux-integrity@vger.kernel.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, chenste@linux.microsoft.com Cc: madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@HansenPartnership.com Subject: [PATCH v7 6/7] ima: make the kexec extra memory configurable Date: Mon, 3 Feb 2025 10:42:55 -0800 Message-Id: <20250203184256.61285-7-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20250203184256.61285-1-chenste@linux.microsoft.com> References: <20250203184256.61285-1-chenste@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250203_104307_266363_3399B0F0 X-CRM114-Status: GOOD ( 15.30 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org 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. From: Tushar Sugandhi Author: Tushar Sugandhi Suggested-by: Stefan Berger Signed-off-by: Tushar Sugandhi Signed-off-by: steven chen --- security/integrity/ima/Kconfig | 10 ++++++++++ security/integrity/ima/ima_kexec.c | 16 ++++++++++------ 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 475c32615006..54b145ae6096 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 + 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, an extra half a page of memory for those + additional measurements will be allocated. + endif diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index d5f004cfeaec..c9c916f69ca7 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -128,22 +128,26 @@ void ima_add_kexec_buffer(struct kimage *image) .buf_min = 0, .buf_max = ULONG_MAX, .top_down = true }; unsigned long binary_runtime_size; - + unsigned long extra_size; /* use more understandable variable names than defined in kbuf */ void *kexec_buffer = NULL; size_t kexec_buffer_size = 0; int ret; /* - * Reserve an extra half page of memory for additional measurements - * added during the kexec load. + * Reserve extra memory for measurements added during kexec. */ - binary_runtime_size = ima_get_binary_runtime_size(); + if (CONFIG_IMA_KEXEC_EXTRA_MEMORY_KB <= 0) + extra_size = PAGE_SIZE / 2; + else + extra_size = CONFIG_IMA_KEXEC_EXTRA_MEMORY_KB * 1024; + binary_runtime_size = ima_get_binary_runtime_size() + extra_size; + if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE) kexec_segment_size = ULONG_MAX; else - kexec_segment_size = ALIGN(ima_get_binary_runtime_size() + - PAGE_SIZE / 2, PAGE_SIZE); + kexec_segment_size = ALIGN(binary_runtime_size, PAGE_SIZE); + if ((kexec_segment_size == ULONG_MAX) || ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages() / 2)) { pr_err("Binary measurement list too large.\n"); -- 2.25.1