Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2d31921..60027c6 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -1,4 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
+ * Integrity Measurement Architecture
+ *
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
*
* Authors:
@@ -7,11 +10,6 @@
* Kylene Hall <kylene@us.ibm.com>
* Mimi Zohar <zohar@us.ibm.com>
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2 of the
- * License.
- *
* File: ima_main.c
* implements the IMA hooks: ima_bprm_check, ima_file_mmap,
* and ima_file_check.
@@ -41,6 +39,10 @@
int ima_hash_algo = HASH_ALGO_SHA1;
static int hash_setup_done;
+static struct notifier_block ima_lsm_policy_notifier = {
+ .notifier_call = ima_lsm_policy_change,
+};
+
static int __init hash_setup(char *str)
{
struct ima_template_desc *template_desc = ima_template_desc_current();
@@ -70,6 +72,27 @@
}
__setup("ima_hash=", hash_setup);
+/* Prevent mmap'ing a file execute that is already mmap'ed write */
+static int mmap_violation_check(enum ima_hooks func, struct file *file,
+ char **pathbuf, const char **pathname,
+ char *filename)
+{
+ struct inode *inode;
+ int rc = 0;
+
+ if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) {
+ rc = -ETXTBSY;
+ inode = file_inode(file);
+
+ if (!*pathbuf) /* ima_rdwr_violation possibly pre-fetched */
+ *pathname = ima_d_path(&file->f_path, pathbuf,
+ filename);
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
+ "mmap_file", "mmapped_writers", rc, 0);
+ }
+ return rc;
+}
+
/*
* ima_rdwr_violation_check
*
@@ -103,7 +126,7 @@
} else {
if (must_measure)
set_bit(IMA_MUST_MEASURE, &iint->atomic_flags);
- if ((atomic_read(&inode->i_writecount) > 0) && must_measure)
+ if (inode_is_open_for_write(inode) && must_measure)
send_writers = true;
}
@@ -172,13 +195,14 @@
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint = NULL;
- struct ima_template_desc *template_desc;
+ struct ima_template_desc *template_desc = NULL;
char *pathbuf = NULL;
char filename[NAME_MAX];
const char *pathname = NULL;
int rc = 0, action, must_appraise = 0;
int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
struct evm_ima_xattr_data *xattr_value = NULL;
+ struct modsig *modsig = NULL;
int xattr_len = 0;
bool violation_check;
enum hash_algo hash_algo;
@@ -190,7 +214,8 @@
* bitmask based on the appraise/audit/measurement policy.
* Included is the appraise submask.
*/
- action = ima_get_action(inode, cred, secid, mask, func, &pcr);
+ action = ima_get_action(inode, cred, secid, mask, func, &pcr,
+ &template_desc);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
if (!action && !violation_check)
@@ -268,20 +293,37 @@
/* Nothing to do, just return existing appraised status */
if (!action) {
- if (must_appraise)
- rc = ima_get_cache_status(iint, func);
+ if (must_appraise) {
+ rc = mmap_violation_check(func, file, &pathbuf,
+ &pathname, filename);
+ if (!rc)
+ rc = ima_get_cache_status(iint, func);
+ }
goto out_locked;
}
- template_desc = ima_template_desc_current();
if ((action & IMA_APPRAISE_SUBMASK) ||
- strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
+ strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
/* read 'security.ima' */
xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
+ /*
+ * Read the appended modsig if allowed by the policy, and allow
+ * an additional measurement list entry, if needed, based on the
+ * template format and whether the file was already measured.
+ */
+ if (iint->flags & IMA_MODSIG_ALLOWED) {
+ rc = ima_read_modsig(func, buf, size, &modsig);
+
+ if (!rc && ima_template_has_modsig(template_desc) &&
+ iint->flags & IMA_MEASURED)
+ action |= IMA_MEASURE;
+ }
+ }
+
hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
- rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
+ rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
if (rc != 0 && rc != -EBADF && rc != -EINVAL)
goto out_locked;
@@ -290,12 +332,16 @@
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname,
- xattr_value, xattr_len, pcr);
+ xattr_value, xattr_len, modsig, pcr,
+ template_desc);
if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
inode_lock(inode);
rc = ima_appraise_measurement(func, iint, file, pathname,
- xattr_value, xattr_len);
+ xattr_value, xattr_len, modsig);
inode_unlock(inode);
+ if (!rc)
+ rc = mmap_violation_check(func, file, &pathbuf,
+ &pathname, filename);
}
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
@@ -308,6 +354,7 @@
rc = -EACCES;
mutex_unlock(&iint->mutex);
kfree(xattr_value);
+ ima_free_modsig(modsig);
out:
if (pathbuf)
__putname(pathbuf);
@@ -395,6 +442,33 @@
EXPORT_SYMBOL_GPL(ima_file_check);
/**
+ * ima_post_create_tmpfile - mark newly created tmpfile as new
+ * @file : newly created tmpfile
+ *
+ * No measuring, appraising or auditing of newly created tmpfiles is needed.
+ * Skip calling process_measurement(), but indicate which newly, created
+ * tmpfiles are in policy.
+ */
+void ima_post_create_tmpfile(struct inode *inode)
+{
+ struct integrity_iint_cache *iint;
+ int must_appraise;
+
+ must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
+ if (!must_appraise)
+ return;
+
+ /* Nothing to do if we can't allocate memory */
+ iint = integrity_inode_get(inode);
+ if (!iint)
+ return;
+
+ /* needed for writing the security xattrs */
+ set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+ iint->ima_file_status = INTEGRITY_PASS;
+}
+
+/**
* ima_post_path_mknod - mark as a new inode
* @dentry: newly created dentry
*
@@ -411,9 +485,13 @@
if (!must_appraise)
return;
+ /* Nothing to do if we can't allocate memory */
iint = integrity_inode_get(inode);
- if (iint)
- iint->flags |= IMA_NEW_FILE;
+ if (!iint)
+ return;
+
+ /* needed for re-opening empty files */
+ iint->flags |= IMA_NEW_FILE;
}
/**
@@ -440,7 +518,7 @@
return 0;
}
-static int read_idmap[READING_MAX_ID] = {
+const int read_idmap[READING_MAX_ID] = {
[READING_FIRMWARE] = FIRMWARE_CHECK,
[READING_FIRMWARE_PREALLOC_BUFFER] = FIRMWARE_CHECK,
[READING_MODULE] = MODULE_CHECK,
@@ -505,20 +583,26 @@
*/
int ima_load_data(enum kernel_load_data_id id)
{
- bool sig_enforce;
+ bool ima_enforce, sig_enforce;
- if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE)
- return 0;
+ ima_enforce =
+ (ima_appraise & IMA_APPRAISE_ENFORCE) == IMA_APPRAISE_ENFORCE;
switch (id) {
case LOADING_KEXEC_IMAGE:
- if (ima_appraise & IMA_APPRAISE_KEXEC) {
+ if (IS_ENABLED(CONFIG_KEXEC_SIG)
+ && arch_ima_get_secureboot()) {
+ pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
+ return -EACCES;
+ }
+
+ if (ima_enforce && (ima_appraise & IMA_APPRAISE_KEXEC)) {
pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
return -EACCES; /* INTEGRITY_UNKNOWN */
}
break;
case LOADING_FIRMWARE:
- if (ima_appraise & IMA_APPRAISE_FIRMWARE) {
+ if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE)) {
pr_err("Prevent firmware sysfs fallback loading.\n");
return -EACCES; /* INTEGRITY_UNKNOWN */
}
@@ -526,7 +610,8 @@
case LOADING_MODULE:
sig_enforce = is_module_sig_enforced();
- if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES)) {
+ if (ima_enforce && (!sig_enforce
+ && (ima_appraise & IMA_APPRAISE_MODULES))) {
pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
return -EACCES; /* INTEGRITY_UNKNOWN */
}
@@ -536,6 +621,80 @@
return 0;
}
+/*
+ * process_buffer_measurement - Measure the buffer to ima log.
+ * @buf: pointer to the buffer that needs to be added to the log.
+ * @size: size of buffer(in bytes).
+ * @eventname: event name to be used for the buffer entry.
+ * @cred: a pointer to a credentials structure for user validation.
+ * @secid: the secid of the task to be validated.
+ *
+ * Based on policy, the buffer is measured into the ima log.
+ */
+static void process_buffer_measurement(const void *buf, int size,
+ const char *eventname,
+ const struct cred *cred, u32 secid)
+{
+ int ret = 0;
+ struct ima_template_entry *entry = NULL;
+ struct integrity_iint_cache iint = {};
+ struct ima_event_data event_data = {.iint = &iint,
+ .filename = eventname,
+ .buf = buf,
+ .buf_len = size};
+ struct ima_template_desc *template_desc = NULL;
+ struct {
+ struct ima_digest_data hdr;
+ char digest[IMA_MAX_DIGEST_SIZE];
+ } hash = {};
+ int violation = 0;
+ int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
+ int action = 0;
+
+ action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr,
+ &template_desc);
+ if (!(action & IMA_MEASURE))
+ return;
+
+ iint.ima_hash = &hash.hdr;
+ iint.ima_hash->algo = ima_hash_algo;
+ iint.ima_hash->length = hash_digest_size[ima_hash_algo];
+
+ ret = ima_calc_buffer_hash(buf, size, iint.ima_hash);
+ if (ret < 0)
+ goto out;
+
+ ret = ima_alloc_init_template(&event_data, &entry, template_desc);
+ if (ret < 0)
+ goto out;
+
+ ret = ima_store_template(entry, violation, NULL, buf, pcr);
+
+ if (ret < 0)
+ ima_free_template_entry(entry);
+
+out:
+ return;
+}
+
+/**
+ * ima_kexec_cmdline - measure kexec cmdline boot args
+ * @buf: pointer to buffer
+ * @size: size of buffer
+ *
+ * Buffers can only be measured, not appraised.
+ */
+void ima_kexec_cmdline(const void *buf, int size)
+{
+ u32 secid;
+
+ if (buf && size != 0) {
+ security_task_getsecid(current, &secid);
+ process_buffer_measurement(buf, size, "kexec-cmdline",
+ current_cred(), secid);
+ }
+}
+
static int __init init_ima(void)
{
int error;
@@ -553,6 +712,10 @@
error = ima_init();
}
+ error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
+ if (error)
+ pr_warn("Couldn't register LSM notifier, error %d\n", error);
+
if (!error)
ima_update_policy_flag();
@@ -560,6 +723,3 @@
}
late_initcall(init_ima); /* Start IMA after the TPM is available */
-
-MODULE_DESCRIPTION("Integrity Measurement Architecture");
-MODULE_LICENSE("GPL");