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 8B080C021B0 for ; Tue, 18 Feb 2025 22:56:37 +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=m5XSyV5sl/OO048Kq+/HhIgyzDGnEXapm0HPn0O8xYQ=; b=YfRQCtGfvBysLIYj8H+r6Gn+63 9VHVK6bjITXka262aaOyFR0TwAS9rrxAjA2YrgLLvavhcWi94ROg7MV+21Xx3fFNB0YUIsEDOsLex c1lPhkLMzR15oakvmv0hAg7FrUgklKGkoSwiLT4N4u8Vyy9HONdwRJokKPNIsgFU9bZ8ACXJxkp3n SLR1tMBCbKD7hZmrNUbpJLEun7mboZr2oNbmCVtZ/HTC64XWRzF8OJI4IIjKC6HXc9TJNjIXf/yaa TueER7oACKzweuL0DcfcNzIEAMnvcuxa+WGqSpMkGj5UJ0Tf9aV4J0JmFxdEze8v9YjsG0VBSNsbL eaOE3CuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkWW5-0000000ACYN-1BNj; Tue, 18 Feb 2025 22:56:37 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tkWUp-0000000ACHZ-0Vcp for kexec@bombadil.infradead.org; Tue, 18 Feb 2025 22:55:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:MIME-Version :References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=m5XSyV5sl/OO048Kq+/HhIgyzDGnEXapm0HPn0O8xYQ=; b=YDGJoo3sYHxwOnSRT8PqUM9bae MAhiO1zJ2aBExnE1HCPmXQ5sIKgHpFt/vNEr80LPVtWxF79Z5JuXWJVJb5eEv7yzEVZneK598yM3O yyuSZGNL1EC4JxCuLcWPTsrs/wumz1JM0m9FyOq/c8McrHjJzTClGVQr0v4yzura8QqjqWdR6Oe/D hZulVxFS1eByw2/vddgVp/nzAOBU08Ct5rh8giDwLSojJRSi+aT7Z4Jntau4LavYYtd//GLmY9Ej2 2Io8IA4nMuv7Z6FlmRleZFkrnIcaAQXrRzKBmH0aXVSDxAmFtfQeyS0sh+a8e1ct6Hc8SpMMPkHTr pUNAZcTA==; Received: from linux.microsoft.com ([13.77.154.182]) by desiato.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tkWUl-000000024Jw-2Rry for kexec@lists.infradead.org; Tue, 18 Feb 2025 22:55:18 +0000 Received: from localhost.localdomain (unknown [167.220.59.4]) by linux.microsoft.com (Postfix) with ESMTPSA id C7E1F20376F2; Tue, 18 Feb 2025 14:55:10 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C7E1F20376F2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1739919310; bh=m5XSyV5sl/OO048Kq+/HhIgyzDGnEXapm0HPn0O8xYQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qW0JCrzC8y6bmwIoagtpf2t/tuRUd3AKlbz8MlS8OeESk9Rh9y1gnPF8cOcdcw2Tr 9YvAcXdDq/ejrS9KbWicsnXaXTwfpzVDp9tJTuZVhjbUDehaVZzW22iIDXrxz3mR7k SCFZrcESBBU6peRjmpvSAClKBQ2rnEIk96wkzCXY= 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 v8 6/7] ima: make the kexec extra memory configurable Date: Tue, 18 Feb 2025 14:55:01 -0800 Message-Id: <20250218225502.747963-7-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20250218225502.747963-1-chenste@linux.microsoft.com> References: <20250218225502.747963-1-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-20250218_225516_118532_AE14BBEE X-CRM114-Status: GOOD ( 15.23 ) 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 --- 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..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 f9dd7ff95b84..6c8c203ad81e 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -126,22 +126,26 @@ 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_memory; /* 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_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