From patchwork Mon Jan 22 18:37:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 13526055 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C721754BD1 for ; Mon, 22 Jan 2024 18:38:15 +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=1705948697; cv=none; b=clK5dkl5vzBzWSanRJhMu37rh8vN5LkGiKMI1xHR/B6ZAeD/tnrIQLEBT0eckGUUzQk6/eOFZ+eXs4+IsI0LHiIDYUVidmTxOVYZHmIkH41CsMITM4qtw2Y4+zWBz0pxTT5uWJiGI8YO5rLe9U5DdUDkWnySb8hy8ghkVE1RJBg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705948697; c=relaxed/simple; bh=rzlEfH4BH1sgznC/UhwvS8OYQKnfy6TxLTON8TxS9zE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=FarGRIzPqs0TPFR9MiE/xz7wjkWiQ9Cgi2ckN/I5zPEdtgJWqW9GCxR9KT8MprvI9ozF7qlb1irnyxgEBwmPvQf+KckwJF9nXHXEqbohXeSPk8MtYmLeQev+LW4NCaEI6eHVZN/IlbIxGQbp+VYSw7IsLEPrloQEdXT9roAF+v8= 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=Oe8BZj6h; 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="Oe8BZj6h" Received: from tushar-HP-Pavilion-Laptop-15-eg0xxx.lan (unknown [50.46.228.62]) by linux.microsoft.com (Postfix) with ESMTPSA id 4D11820E2C0A; Mon, 22 Jan 2024 10:38:15 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 4D11820E2C0A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1705948695; bh=qJHN560TUZe/5m2Gya0jv8CgnkhIqfBUCJMwNbKONAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Oe8BZj6hMBvY5o1xChVYXTZ58hlM5FZ1WkPHd6CmU76c37WMkBJMuHaS6r1AlLa4E cFLEsSo4gkeJGI0Ozgo0IyGtqNMFy1xpsxKaTchsKKnFdZsYkusfDzyDrS6LrJ+tT+ AdBEZhp5IZCpFMI3NL4G6AYEiwc9FlQgxHENtYtA= From: Tushar Sugandhi To: zohar@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, stefanb@linux.ibm.com, ebiederm@xmission.com, noodles@fb.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org Cc: code@tyhicks.com, nramas@linux.microsoft.com, paul@paul-moore.com Subject: [PATCH v4 1/7] ima: define and call ima_alloc_kexec_file_buf Date: Mon, 22 Jan 2024 10:37:58 -0800 Message-Id: <20240122183804.3293904-2-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240122183804.3293904-1-tusharsu@linux.microsoft.com> References: <20240122183804.3293904-1-tusharsu@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Refactor ima_dump_measurement_list() to move the memory allocation part to a separate function ima_alloc_kexec_file_buf() which allocates buffer of size 'kexec_segment_size' at kexec 'load'. Make the local variable ima_kexec_file in function ima_dump_measurement_list() as local static to the file, so that it can be accessed from ima_alloc_kexec_file_buf(). Make necessary changes to the function ima_add_kexec_buffer() to call the above two functions. Signed-off-by: Tushar Sugandhi --- security/integrity/ima/ima_kexec.c | 96 +++++++++++++++++++++--------- 1 file changed, 67 insertions(+), 29 deletions(-) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 419dc405c831..99daac355c70 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -15,62 +15,93 @@ #include "ima.h" #ifdef CONFIG_IMA_KEXEC +static struct seq_file ima_kexec_file; + +static void ima_free_kexec_file_buf(struct seq_file *sf) +{ + vfree(sf->buf); + sf->buf = NULL; + sf->size = 0; + sf->read_pos = 0; + sf->count = 0; +} + +static int ima_alloc_kexec_file_buf(size_t segment_size) +{ + /* + * kexec 'load' may be called multiple times. + * Free and realloc the buffer only if the segment_size is + * changed from the previous kexec 'load' call. + */ + if (ima_kexec_file.buf && + ima_kexec_file.size == segment_size && + ima_kexec_file.read_pos == 0 && + ima_kexec_file.count == sizeof(struct ima_kexec_hdr)) + return 0; + + ima_free_kexec_file_buf(&ima_kexec_file); + + /* segment size can't change between kexec load and execute */ + ima_kexec_file.buf = vmalloc(segment_size); + if (!ima_kexec_file.buf) + return -ENOMEM; + + ima_kexec_file.size = segment_size; + ima_kexec_file.read_pos = 0; + ima_kexec_file.count = sizeof(struct ima_kexec_hdr); /* reserved space */ + + return 0; +} + static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, unsigned long segment_size) { struct ima_queue_entry *qe; - struct seq_file file; struct ima_kexec_hdr khdr; - int ret = 0; - /* segment size can't change between kexec load and execute */ - file.buf = vmalloc(segment_size); - if (!file.buf) { - ret = -ENOMEM; - goto out; + if (!ima_kexec_file.buf) { + *buffer_size = 0; + *buffer = NULL; + pr_err("%s: Kexec file buf not allocated\n", __func__); + return -EINVAL; } - file.size = segment_size; - file.read_pos = 0; - file.count = sizeof(khdr); /* reserved space */ - memset(&khdr, 0, sizeof(khdr)); khdr.version = 1; + + /* Copy as many IMA measurements list records as possible */ list_for_each_entry_rcu(qe, &ima_measurements, later) { - if (file.count < file.size) { + if (ima_kexec_file.count < ima_kexec_file.size) { khdr.count++; - ima_measurements_show(&file, qe); + ima_measurements_show(&ima_kexec_file, qe); } else { - ret = -EINVAL; + pr_err("%s: IMA log file is too big for Kexec buf\n", + __func__); break; } } - if (ret < 0) - goto out; - /* * fill in reserved space with some buffer details * (eg. version, buffer size, number of measurements) */ - khdr.buffer_size = file.count; + khdr.buffer_size = ima_kexec_file.count; if (ima_canonical_fmt) { khdr.version = cpu_to_le16(khdr.version); khdr.count = cpu_to_le64(khdr.count); khdr.buffer_size = cpu_to_le64(khdr.buffer_size); } - memcpy(file.buf, &khdr, sizeof(khdr)); + memcpy(ima_kexec_file.buf, &khdr, sizeof(khdr)); print_hex_dump_debug("ima dump: ", DUMP_PREFIX_NONE, 16, 1, - file.buf, file.count < 100 ? file.count : 100, + ima_kexec_file.buf, ima_kexec_file.count < 100 ? + ima_kexec_file.count : 100, true); - *buffer_size = file.count; - *buffer = file.buf; -out: - if (ret == -EINVAL) - vfree(file.buf); - return ret; + *buffer_size = ima_kexec_file.count; + *buffer = ima_kexec_file.buf; + + return 0; } /* @@ -108,13 +139,20 @@ void ima_add_kexec_buffer(struct kimage *image) return; } - ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, - kexec_segment_size); - if (!kexec_buffer) { + ret = ima_alloc_kexec_file_buf(kexec_segment_size); + if (ret < 0) { pr_err("Not enough memory for the kexec measurement buffer.\n"); return; } + ret = ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, + kexec_segment_size); + if (ret < 0) { + pr_err("%s: Failed to dump IMA measurements. Error:%d.\n", + __func__, ret); + return; + } + kbuf.buffer = kexec_buffer; kbuf.bufsz = kexec_buffer_size; kbuf.memsz = kexec_segment_size;