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 628ADC3601A for ; Wed, 2 Apr 2025 12:51:45 +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=akIJhi5dOsbPwjFtHYsWPzeWZ2NiSa/DdRwiLCQ9Fbg=; b=pPRWRXCpnA6u8cTggf8/PaJ+ik CdLwkvzQ3KwBVlMepuPM+YvrWroAJ25Z8RWQZ0JQhgmaZh678BYgXCieYtRoYFrV2ASw0kAmTmuNr gN9D29lYm0uKMkI2Mk9sC3lVOeNfxYQb7gALe91wwNHdEWIeYvMuTTaLxcS3IYhzuqyiAIVjSfZJK 5gT/wAcriJHTbwAk8S0aS1yTo726PkeH5cTCvWNSsBBa71eeVhkoDUtYW/l2NCYaVCLGnpdv5PS5A r3YNv1GV5uyhMHeBnlK8lryXBiB83FuVog4Bmq+nfgAiMEiarU12nOnOjSq0Jz8x9US4Ou82kM0+O r9xfOT2w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzxZH-0000000695k-2PYe; Wed, 02 Apr 2025 12:51:43 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tzxVc-000000068C3-1xYD for kexec@lists.infradead.org; Wed, 02 Apr 2025 12:47:57 +0000 Received: from DESKTOP-VOT081N.hsd1.ga.comcast.net (unknown [20.114.144.49]) by linux.microsoft.com (Postfix) with ESMTPSA id D3F0C2041310; Wed, 2 Apr 2025 05:47:53 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D3F0C2041310 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1743598075; bh=akIJhi5dOsbPwjFtHYsWPzeWZ2NiSa/DdRwiLCQ9Fbg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rNCzdP9dHIJ0owIlx8+IhWD9u+n9u7qJfksu7jR/sDVdDhlBaAj9YGY+qIKJu6qe+ m0CV0LLATNeXBWXvKHF9nLIIdf6iyPRtCYZBOlSju/5NftIG59OdbEUSwNDpp6HgJ8 UlGkVOlj4WuolTyrf5WwPtYeb5Db5uqM8DxwDrec= 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, 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 Subject: [PATCH v11 8/9] ima: make the kexec extra memory configurable Date: Wed, 2 Apr 2025 05:47:21 -0700 Message-ID: <20250402124725.5601-9-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250402124725.5601-1-chenste@linux.microsoft.com> References: <20250402124725.5601-1-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-20250402_054756_562897_FDA9E736 X-CRM114-Status: GOOD ( 15.52 ) 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. 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 + 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 diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index ed867734ee70..d1c9d369ba08 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -118,6 +118,7 @@ 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_memory; /* use more understandable variable names than defined in kbuf */ size_t kexec_buffer_size = 0; @@ -125,15 +126,20 @@ void ima_add_kexec_buffer(struct kimage *image) 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_memory = PAGE_SIZE / 2; + else + extra_memory = CONFIG_IMA_KEXEC_EXTRA_MEMORY_KB * 1024; + + binary_runtime_size = ima_get_binary_runtime_size() + extra_memory; + 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