[v8,09/10] ima: define a canonical binary_runtime_measurements list format

Message ID	1480554346-29071-10-git-send-email-zohar@linux.vnet.ibm.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> Gateway: Authorized Use Only! Violators will be prosecuted for <linux-security-module@vger.kernel.org> from <zohar@linux.vnet.ibm.com>; Thu, 1 Dec 2016 06:36:55 +0530 Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 1 Dec 2016 06:36:54 +0530 From: Mimi Zohar <zohar@linux.vnet.ibm.com> To: linux-security-module <linux-security-module@vger.kernel.org> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>, Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>, linux-ima-devel@lists.sourceforge.net, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>, Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Subject: [PATCH v8 09/10] ima: define a canonical binary_runtime_measurements list format Date: Wed, 30 Nov 2016 20:05:45 -0500 In-Reply-To: <1480554346-29071-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1480554346-29071-1-git-send-email-zohar@linux.vnet.ibm.com> Message-Id: <1480554346-29071-10-git-send-email-zohar@linux.vnet.ibm.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 37babf91f2cb..3ee81afad7e9 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1641,6 +1641,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. The builtin appraise policy appraises all files owned by uid=0. + ima_canonical_fmt [IMA] + Use the canonical format for the binary runtime + measurements, instead of host native format. + ima_hash= [IMA] Format: { md5 | sha1 | rmd160 | sha256 | sha384 | sha512 | ... } diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 6b0540ad189f..5e6180a4da7d 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -122,6 +122,12 @@ void ima_load_kexec_buffer(void); static inline void ima_load_kexec_buffer(void) {} #endif /* CONFIG_HAVE_IMA_KEXEC */ +/* + * The default binary_runtime_measurements list format is defined as the + * platform native format. The canonical format is defined as little-endian. + */ +extern bool ima_canonical_fmt; + /* Internal IMA function definitions */ int ima_init(void); int ima_fs_init(void); diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 10bea0125fa1..ca303e5d2b94 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -28,6 +28,16 @@ static DEFINE_MUTEX(ima_write_mutex); +bool ima_canonical_fmt; +static int __init default_canonical_fmt_setup(char *str) +{ +#ifdef __BIG_ENDIAN + ima_canonical_fmt = 1; +#endif + return 1; +} +__setup("ima_canonical_fmt", default_canonical_fmt_setup); + static int valid_policy = 1; #define TMPBUFLEN 12 static ssize_t ima_show_htable_value(char __user *buf, size_t count, @@ -122,7 +132,7 @@ int ima_measurements_show(struct seq_file *m, void *v) struct ima_queue_entry *qe = v; struct ima_template_entry *e; char *template_name; - int namelen; + u32 pcr, namelen, template_data_len; /* temporary fields */ bool is_ima_template = false; int i; @@ -139,25 +149,29 @@ int ima_measurements_show(struct seq_file *m, void *v) * PCR used defaults to the same (config option) in * little-endian format, unless set in policy */ - ima_putc(m, &e->pcr, sizeof(e->pcr)); + pcr = !ima_canonical_fmt ? e->pcr : cpu_to_le32(e->pcr); + ima_putc(m, &pcr, sizeof(e->pcr)); /* 2nd: template digest */ ima_putc(m, e->digest, TPM_DIGEST_SIZE); /* 3rd: template name size */ - namelen = strlen(template_name); + namelen = !ima_canonical_fmt ? strlen(template_name) : + cpu_to_le32(strlen(template_name)); ima_putc(m, &namelen, sizeof(namelen)); /* 4th: template name */ - ima_putc(m, template_name, namelen); + ima_putc(m, template_name, strlen(template_name)); /* 5th: template length (except for 'ima' template) */ if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0) is_ima_template = true; - if (!is_ima_template) - ima_putc(m, &e->template_data_len, - sizeof(e->template_data_len)); + if (!is_ima_template) { + template_data_len = !ima_canonical_fmt ? e->template_data_len : + cpu_to_le32(e->template_data_len); + ima_putc(m, &template_data_len, sizeof(e->template_data_len)); + } /* 6th: template specific data */ for (i = 0; i < e->template_desc->num_fields; i++) { diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 2c4824ac1ce1..e473eee913cb 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -21,8 +21,7 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, { struct ima_queue_entry *qe; struct seq_file file; - struct ima_kexec_hdr khdr = { - .version = 1, .buffer_size = 0, .count = 0}; + struct ima_kexec_hdr khdr; int ret = 0; /* segment size can't change between kexec load and execute */ @@ -36,6 +35,8 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, file.read_pos = 0; file.count = sizeof(khdr); /* reserved space */ + memset(&khdr, 0, sizeof(khdr)); + khdr.version = 1; list_for_each_entry_rcu(qe, &ima_measurements, later) { if (file.count < file.size) { khdr.count++; @@ -54,7 +55,13 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, * (eg. version, buffer size, number of measurements) */ khdr.buffer_size = 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)); + print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE, 16, 1, file.buf, file.count < 100 ? file.count : 100, true); diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index 16bbb5a80fc8..cebb37c63629 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -302,6 +302,9 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc, } offset += sizeof(*field_data); + if (ima_canonical_fmt) + field_data->len = le32_to_cpu(field_data->len); + if (offset > (template_data_size - field_data->len)) { pr_err("Restoring the template field data failed\n"); ret = -EINVAL; @@ -352,7 +355,7 @@ int ima_restore_measurement_list(loff_t size, void *buf) struct binary_data_v1 *data_v1; void *bufp = buf + sizeof(*khdr); - void *bufendp = buf + khdr->buffer_size; + void *bufendp; struct ima_template_entry *entry; struct ima_template_desc *template_desc; unsigned long count = 0; @@ -361,6 +364,12 @@ int ima_restore_measurement_list(loff_t size, void *buf) if (!buf || size < sizeof(*khdr)) return 0; + if (ima_canonical_fmt) { + khdr->version = le16_to_cpu(khdr->version); + khdr->count = le64_to_cpu(khdr->count); + khdr->buffer_size = le64_to_cpu(khdr->buffer_size); + } + if (khdr->version != 1) { pr_err("attempting to restore a incompatible measurement list"); return -EINVAL; @@ -376,6 +385,7 @@ int ima_restore_measurement_list(loff_t size, void *buf) * v1 format: pcr, digest, template-name-len, template-name, * template-data-size, template-data */ + bufendp = buf + khdr->buffer_size; while ((bufp < bufendp) && (count++ < khdr->count)) { hdr_v1 = bufp; if (bufp > (bufendp - sizeof(*hdr_v1))) { @@ -385,6 +395,10 @@ int ima_restore_measurement_list(loff_t size, void *buf) } bufp += sizeof(*hdr_v1); + if (ima_canonical_fmt) + hdr_v1->template_name_len = + le32_to_cpu(hdr_v1->template_name_len); + if ((hdr_v1->template_name_len >= MAX_TEMPLATE_NAME_LEN) || (bufp > (bufendp - hdr_v1->template_name_len))) { pr_err("attempting to restore a template name \ @@ -434,6 +448,10 @@ int ima_restore_measurement_list(loff_t size, void *buf) } bufp += (u_int8_t) sizeof(data_v1->template_data_size); + if (ima_canonical_fmt) + data_v1->template_data_size = + le32_to_cpu(data_v1->template_data_size); + if (bufp > (bufendp - data_v1->template_data_size)) { pr_err("restoring the template data failed\n"); ret = -EINVAL; @@ -449,7 +467,8 @@ int ima_restore_measurement_list(loff_t size, void *buf) break; memcpy(entry->digest, hdr_v1->digest, TPM_DIGEST_SIZE); - entry->pcr = hdr_v1->pcr; + entry->pcr = + !ima_canonical_fmt ? hdr_v1->pcr : le32_to_cpu(hdr_v1->pcr); ret = ima_restore_measurement_entry(entry); if (ret < 0) break; diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index f9bae04ba176..f9ba37b3928d 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -103,8 +103,11 @@ static void ima_show_template_data_binary(struct seq_file *m, u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ? strlen(field_data->data) : field_data->len; - if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) - ima_putc(m, &len, sizeof(len)); + if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) { + u32 field_len = !ima_canonical_fmt ? len : cpu_to_le32(len); + + ima_putc(m, &field_len, sizeof(field_len)); + } if (!len) return;

[v8,09/10] ima: define a canonical binary_runtime_measurements list format

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Patch