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 3A8DEC02193 for ; Mon, 3 Feb 2025 23:20:47 +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=842zmq7II7peAIQB44phcmR7CRWWIlAqh7HOqyXvZx8=; b=umOvmB5AIKpOV7iETCWKPW+CrD 04xgBAMa4NPau6oqcN9G6yL5tkzrwXkOnXR7TXkU3tkV+Zc33EeuMd2nBRVVLHz61FdtJ5cJ4cSTU dgPAmx00EHz+kDKsYL2uVBSmwSVYbhf73aNIUYundqqWQsZS7COsoF3vP8LkYJg5R+3HRQdcG8gtv q4pi1ykLabnpNOTezNZKP6JpF/Jhqd3n3U6BdG/EhiXxAVDHiYn9vZG4f0FbV2zUomBVqzNaI70tQ CRlOKqnGzg7e/xliDXeSUbko0LcHeTrvc+z6x+gzVpjcOfNl/1SecpmBfpEjlN5G9i6PvL5WSTkxq RuwBe07g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tf5kE-0000000Gs7W-3xxL; Mon, 03 Feb 2025 23:20:46 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tf5kB-0000000Gs4K-40NS for kexec@lists.infradead.org; Mon, 03 Feb 2025 23:20:45 +0000 Received: from localhost.localdomain (unknown [167.220.59.4]) by linux.microsoft.com (Postfix) with ESMTPSA id CF8C720BCAF2; Mon, 3 Feb 2025 15:20:41 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CF8C720BCAF2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1738624841; bh=842zmq7II7peAIQB44phcmR7CRWWIlAqh7HOqyXvZx8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AJudZl8PsKuB6X5xWIc6BBG8dcVEhVVZr8Z67olbwHLQaqsDZwtFAIdaiqBKJ1oA7 vB3e+2KtTygieJNsdAZjY6LmkiXoz4bMFo2Gu98u59KA6VrL1lbW+IdvYiQhduKupM Ae6IU/C0gq4iAo47bnHREtHmFYYzyXmCX7h8D7zA= 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, chenste@linux.microsoft.com Cc: madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@HansenPartnership.com Subject: [PATCH v7 5/7] ima: kexec: move IMA log copy from kexec load to execute Date: Mon, 3 Feb 2025 15:20:31 -0800 Message-Id: <20250203232033.64123-7-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20250203232033.64123-1-chenste@linux.microsoft.com> References: <20250203232033.64123-1-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_152044_039782_ECE43A31 X-CRM114-Status: GOOD ( 18.67 ) 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 ima_dump_measurement_list() is called during kexec 'load', which may result in loss of IMA measurements during kexec soft reboot. It needs to be called during kexec 'execute'. This patch includes the following changes: - Implement kimage_file_post_load() function to be invoked after the new Kernel image has been loaded for kexec. - Call kimage_file_post_load() from kexec_file_load() syscall only for kexec soft reboot scenarios and not for KEXEC_FILE_ON_CRASH. It will map the IMA segment, and register reboot notifier for the function ima_update_kexec_buffer() which would copy the IMA log at kexec soft reboot. - Make kexec_segment_size variable local static to the file, for it to be accessible both during kexec 'load' and 'execute'. - Move ima_dump_measurement_list() call from ima_add_kexec_buffer() to ima_update_kexec_buffer(). - Remove ima_reset_kexec_file() call from ima_add_kexec_buffer(), now that the buffer is being copied at kexec 'execute', and resetting the file at kexec 'load' will corrupt the buffer. Author: Tushar Sugandhi Reviewed-by: Tyler Hicks Signed-off-by: Tushar Sugandhi Signed-off-by: steven chen --- kernel/kexec_file.c | 8 ++++++ security/integrity/ima/ima_kexec.c | 43 +++++++++++++++++++----------- 2 files changed, 36 insertions(+), 15 deletions(-) diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index a3370a0dce20..a523cd209bfc 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -202,6 +202,11 @@ kimage_validate_signature(struct kimage *image) } #endif +static void kimage_file_post_load(struct kimage *image) +{ + ima_kexec_post_load(image); +} + /* * In file mode list of segments is prepared by kernel. Copy relevant * data from user space, do error checking, prepare segment list @@ -429,6 +434,9 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd, kimage_terminate(image); + if (!(flags & KEXEC_FILE_ON_CRASH)) + kimage_file_post_load(image); + ret = machine_kexec_post_load(image); if (ret) goto out; diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 854b90d34e2d..d5f004cfeaec 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -19,6 +19,7 @@ #ifdef CONFIG_IMA_KEXEC static struct seq_file ima_kexec_file; static void *ima_kexec_buffer; +static size_t kexec_segment_size; static bool ima_kexec_update_registered; static void ima_reset_kexec_file(struct seq_file *sf) @@ -131,7 +132,6 @@ void ima_add_kexec_buffer(struct kimage *image) /* use more understandable variable names than defined in kbuf */ void *kexec_buffer = NULL; size_t kexec_buffer_size = 0; - size_t kexec_segment_size; int ret; /* @@ -156,13 +156,6 @@ void ima_add_kexec_buffer(struct kimage *image) return; } - ret = ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, - kexec_segment_size); - if (ret < 0) { - pr_err("Failed to dump IMA measurements. Error:%d.\n", ret); - return; - } - kbuf.buffer = kexec_buffer; kbuf.bufsz = kexec_buffer_size; kbuf.memsz = kexec_segment_size; @@ -180,12 +173,6 @@ void ima_add_kexec_buffer(struct kimage *image) image->ima_segment_index = image->nr_segments - 1; image->is_ima_segment_index_set = true; - /* - * kexec owns kexec_buffer after kexec_add_buffer() is called - * and it will vfree() that buffer. - */ - ima_reset_kexec_file(&ima_kexec_file); - kexec_dprintk("kexec measurement buffer for the loaded kernel at 0x%lx.\n", kbuf.mem); } @@ -196,7 +183,33 @@ void ima_add_kexec_buffer(struct kimage *image) static int ima_update_kexec_buffer(struct notifier_block *self, unsigned long action, void *data) { - return NOTIFY_OK; + void *buf = NULL; + size_t buf_size = 0; + int ret = NOTIFY_OK; + + if (!kexec_in_progress) { + pr_info("No kexec in progress.\n"); + return ret; + } + + if (!ima_kexec_buffer) { + pr_err("Kexec buffer not set.\n"); + return ret; + } + + ret = ima_dump_measurement_list(&buf_size, &buf, + kexec_segment_size); + + if (ret) + pr_err("Dump measurements failed. Error:%d\n", ret); + + if (buf_size != 0) + memcpy(ima_kexec_buffer, buf, buf_size); + + kimage_unmap_segment(ima_kexec_buffer); + ima_kexec_buffer = NULL; + + return ret; } struct notifier_block update_buffer_nb = { -- 2.25.1