From patchwork Fri Jan 24 22:55:45 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: steven chen X-Patchwork-Id: 13950018 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 122AC1EEA43; Fri, 24 Jan 2025 22:55:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737759360; cv=none; b=RtZ0i5+W9QljPm5a2c9h04l9EC6ZrKST3NFp0HDF/2olplE1VkNlpZBk7P9Z35ahd4R4BwuKUYg0Awkw0IwlFV0/6LpjCtr2fv89pZT9Uoax5lK1p+hlBB6QHojyRoUfJ9i6foJv1BkT47MtamToeeImlJH0sSvH/QZ4NN6beSQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737759360; c=relaxed/simple; bh=Pxre783PzACACeV34ZisP2a76BNcKKtQ+N5YCrzjsfo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qLtF43Q6iZY32U1lWOGqPgFYfVIY0ESuQgZCvf/o46nqzC2JFr4KUtUWjpyFafcDFxrSkqgEdfdLZwae29E+eQPNAp8zNrPWpKUKTZpd8ob8uny+WoaEQYboqxb1ogNtn1cEPtX24fAwuug1bf4NfJxYP1jrBEAlsxgJmCmFyH8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=FbSTWpys; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="FbSTWpys" Received: from localhost.localdomain (unknown [167.220.59.4]) by linux.microsoft.com (Postfix) with ESMTPSA id 35433210D0D8; Fri, 24 Jan 2025 14:55:57 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 35433210D0D8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1737759357; bh=SToxeWWYWW6LWJe1NQgF6XwKRGWLZYBJcF4B7FrieaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FbSTWpysH5IZGaxG2nIWAj17VFWOJEM+rzPr2XTkuwbKrd8kaWJXPTtI70i/Ag8iB Mrs30XiGb6bALgfqq4x47ZFIgqn1tLN1OJ+d64VTqr7RXV6NKJeR5+TMSjitw4rxgO x3S4BY9Xy0qU1CYifPUGe6tHUSb92zdFlmKrCSOk= From: steven chen To: zohar@linux.ibm.com, stefanb@linux.ibm.com, roberto.sassu@huaweicloud.com, petr@tesarici.cz, eric.snowberg@oracle.com, paul@paul-moore.com, code@tyhicks.com, nramas@linux.microsoft.com, James.Bottomley@HansenPartnership.com, madvenka@linux.microsoft.com Cc: linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, chenste@linux.microsoft.com Subject: [PATCH v6 5/7] ima: kexec: move IMA log copy from kexec load to execute Date: Fri, 24 Jan 2025 14:55:45 -0800 Message-Id: <20250124225547.22684-6-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20250124225547.22684-1-chenste@linux.microsoft.com> References: <20250124225547.22684-1-chenste@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 4ff3ba0f3e8e..d05ce3ee2e53 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -186,6 +186,11 @@ 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 @@ -413,6 +418,9 @@ 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 = {