[PATCH v12 05/26] ima: Move ima_htable into ima_namespace

Stefan Berger
2022-04-20T14:10:26Z

Move ima_htable into ima_namespace. This way a front-end like
securityfs can show the number of measurement records and number of
violations of an IMA namespace.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
---
security/integrity/ima/ima.h | 33 +++++++++++++---------
security/integrity/ima/ima_api.c | 18 +++++++-----
security/integrity/ima/ima_fs.c | 8 ++++--
security/integrity/ima/ima_init.c | 7 +++--
security/integrity/ima/ima_init_ima_ns.c | 4 +++
security/integrity/ima/ima_kexec.c | 3 +-
security/integrity/ima/ima_main.c | 14 +++++----
security/integrity/ima/ima_queue.c | 36 ++++++++++++------------
security/integrity/ima/ima_template.c | 5 ++--
9 files changed, 76 insertions(+), 52 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 2305bf223a98..78798cfcf46c 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -117,6 +117,12 @@ struct ima_kexec_hdr {
u64 count;
};

+struct ima_h_table {
+ atomic_long_t len; /* number of stored measurements in the list */
+ atomic_long_t violations;
+ struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
+};
+
struct ima_namespace {
/* policy rules */
struct list_head ima_default_rules; /* Kconfig, builtin & arch rules */
@@ -128,6 +134,8 @@ struct ima_namespace {

/* An array of architecture specific rules */
struct ima_rule_entry *arch_policy_entry;
+
+ struct ima_h_table ima_htable;
} __randomize_layout;
extern struct ima_namespace init_ima_ns;

@@ -149,7 +157,8 @@ extern bool ima_canonical_fmt;
int ima_init(void);
int ima_fs_init(void);
int ima_ns_init(void);
-int ima_add_template_entry(struct ima_template_entry *entry, int violation,
+int ima_add_template_entry(struct ima_namespace *ns,
+ struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode,
const unsigned char *filename);
int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
@@ -158,7 +167,8 @@ int ima_calc_buffer_hash(const void *buf, loff_t len,
int ima_calc_field_array_hash(struct ima_field_data *field_data,
struct ima_template_entry *entry);
int ima_calc_boot_aggregate(struct ima_digest_data *hash);
-void ima_add_violation(struct file *file, const unsigned char *filename,
+void ima_add_violation(struct ima_namespace *ns,
+ struct file *file, const unsigned char *filename,
struct integrity_iint_cache *iint,
const char *op, const char *cause);
int ima_init_crypto(void);
@@ -171,8 +181,10 @@ struct ima_template_desc *ima_template_desc_current(void);
struct ima_template_desc *ima_template_desc_buf(void);
struct ima_template_desc *lookup_template_desc(const char *name);
bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
-int ima_restore_measurement_entry(struct ima_template_entry *entry);
-int ima_restore_measurement_list(loff_t bufsize, void *buf);
+int ima_restore_measurement_entry(struct ima_namespace *ns,
+ struct ima_template_entry *entry);
+int ima_restore_measurement_list(struct ima_namespace *ns,
+ loff_t bufsize, void *buf);
int ima_measurements_show(struct seq_file *m, void *v);
unsigned long ima_get_binary_runtime_size(void);
int ima_init_template(void);
@@ -186,13 +198,6 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
*/
extern spinlock_t ima_queue_lock;

-struct ima_h_table {
- atomic_long_t len; /* number of stored measurements in the list */
- atomic_long_t violations;
- struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
-};
-extern struct ima_h_table ima_htable;
-
static inline unsigned int ima_hash_key(u8 *digest)
{
/* there is no point in taking a hash of part of a digest */
@@ -277,7 +282,8 @@ int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file, void *buf, loff_t size,
enum hash_algo algo, struct modsig *modsig);
-void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
+void ima_store_measurement(struct ima_namespace *ns,
+ struct integrity_iint_cache *iint, struct file *file,
const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
int xattr_len, const struct modsig *modsig, int pcr,
@@ -293,7 +299,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint,
int ima_alloc_init_template(struct ima_event_data *event_data,
struct ima_template_entry **entry,
struct ima_template_desc *template_desc);
-int ima_store_template(struct ima_template_entry *entry, int violation,
+int ima_store_template(struct ima_namespace *ns,
+ struct ima_template_entry *entry, int violation,
struct inode *inode,
const unsigned char *filename, int pcr);
void ima_free_template_entry(struct ima_template_entry *entry);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 90ef246a9f43..1b6c3e6174cd 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -99,7 +99,8 @@ int ima_alloc_init_template(struct ima_event_data *event_data,
*
* Returns 0 on success, error code otherwise
*/
-int ima_store_template(struct ima_template_entry *entry,
+int ima_store_template(struct ima_namespace *ns,
+ struct ima_template_entry *entry,
int violation, struct inode *inode,
const unsigned char *filename, int pcr)
{
@@ -119,7 +120,8 @@ int ima_store_template(struct ima_template_entry *entry,
}
}
entry->pcr = pcr;
- result = ima_add_template_entry(entry, violation, op, inode, filename);
+ result = ima_add_template_entry(ns, entry, violation, op, inode,
+ filename);
return result;
}

@@ -130,7 +132,8 @@ int ima_store_template(struct ima_template_entry *entry,
* By extending the PCR with 0xFF's instead of with zeroes, the PCR
* value is invalidated.
*/
-void ima_add_violation(struct file *file, const unsigned char *filename,
+void ima_add_violation(struct ima_namespace *ns,
+ struct file *file, const unsigned char *filename,
struct integrity_iint_cache *iint,
const char *op, const char *cause)
{
@@ -144,14 +147,14 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
int result;

/* can overflow, only indicator */
- atomic_long_inc(&ima_htable.violations);
+ atomic_long_inc(&ns->ima_htable.violations);

result = ima_alloc_init_template(&event_data, &entry, NULL);
if (result < 0) {
result = -ENOMEM;
goto err_out;
}
- result = ima_store_template(entry, violation, inode,
+ result = ima_store_template(ns, entry, violation, inode,
filename, CONFIG_IMA_MEASURE_PCR_IDX);
if (result < 0)
ima_free_template_entry(entry);
@@ -297,7 +300,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
*
* Must be called with iint->mutex held.
*/
-void ima_store_measurement(struct integrity_iint_cache *iint,
+void ima_store_measurement(struct ima_namespace *ns,
+ struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
int xattr_len, const struct modsig *modsig, int pcr,
@@ -332,7 +336,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
return;
}

- result = ima_store_template(entry, violation, inode, filename, pcr);
+ result = ima_store_template(ns, entry, violation, inode, filename, pcr);
if ((!result || result == -EEXIST) && !(file->f_flags & O_DIRECT)) {
iint->flags |= IMA_MEASURED;
iint->measured_pcrs |= (0x1 << pcr);
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index f7ad93a56982..dca7fe32d65e 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -52,7 +52,10 @@ static ssize_t ima_show_htable_violations(struct file *filp,
char __user *buf,
size_t count, loff_t *ppos)
{
- return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
+ struct ima_namespace *ns = &init_ima_ns;
+
+ return ima_show_htable_value(buf, count, ppos,
+ &ns->ima_htable.violations);
}

static const struct file_operations ima_htable_violations_ops = {
@@ -64,8 +67,9 @@ static ssize_t ima_show_measurements_count(struct file *filp,
char __user *buf,
size_t count, loff_t *ppos)
{
- return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
+ struct ima_namespace *ns = &init_ima_ns;

+ return ima_show_htable_value(buf, count, ppos, &ns->ima_htable.len);
}

static const struct file_operations ima_measurements_count_ops = {
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 7e5b4187035d..47c9d561532e 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -39,7 +39,7 @@ struct tpm_chip *ima_tpm_chip;
* a different value.) Violations add a zero entry to the measurement
* list and extend the aggregate PCR value with ff...ff's.
*/
-static int __init ima_add_boot_aggregate(void)
+static int __init ima_add_boot_aggregate(struct ima_namespace *ns)
{
static const char op[] = "add_boot_aggregate";
const char *audit_cause = "ENOMEM";
@@ -83,7 +83,7 @@ static int __init ima_add_boot_aggregate(void)
goto err_out;
}

- result = ima_store_template(entry, violation, NULL,
+ result = ima_store_template(ns, entry, violation, NULL,
boot_aggregate_name,
CONFIG_IMA_MEASURE_PCR_IDX);
if (result < 0) {
@@ -142,7 +142,8 @@ int __init ima_init(void)
rc = ima_init_digests();
if (rc != 0)
return rc;
- rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */
+ /* boot aggregate must be first entry */
+ rc = ima_add_boot_aggregate(&init_ima_ns);
if (rc != 0)
return rc;

diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c
index ae33621c3955..1945fa8cfc4d 100644
--- a/security/integrity/ima/ima_init_ima_ns.c
+++ b/security/integrity/ima/ima_init_ima_ns.c
@@ -17,6 +17,10 @@ static int ima_init_namespace(struct ima_namespace *ns)
ns->ima_policy_flag = 0;
ns->arch_policy_entry = NULL;

+ atomic_long_set(&ns->ima_htable.len, 0);
+ atomic_long_set(&ns->ima_htable.violations, 0);
+ memset(&ns->ima_htable.queue, 0, sizeof(ns->ima_htable.queue));
+
return 0;
}

diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
index 13753136f03f..d7cc5cca6f84 100644
--- a/security/integrity/ima/ima_kexec.c
+++ b/security/integrity/ima/ima_kexec.c
@@ -146,7 +146,8 @@ void ima_load_kexec_buffer(void)
rc = ima_get_kexec_buffer(&kexec_buffer, &kexec_buffer_size);
switch (rc) {
case 0:
- rc = ima_restore_measurement_list(kexec_buffer_size,
+ rc = ima_restore_measurement_list(&init_ima_ns,
+ kexec_buffer_size,
kexec_buffer);
if (rc != 0)
pr_err("Failed to restore the measurement list: %d\n",
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 400865c521dd..005f9e784e7b 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -112,7 +112,8 @@ static int mmap_violation_check(enum ima_hooks func, struct file *file,
* could result in a file measurement error.
*
*/
-static void ima_rdwr_violation_check(struct file *file,
+static void ima_rdwr_violation_check(struct ima_namespace *ns,
+ struct file *file,
struct integrity_iint_cache *iint,
int must_measure,
char **pathbuf,
@@ -145,10 +146,10 @@ static void ima_rdwr_violation_check(struct file *file,
*pathname = ima_d_path(&file->f_path, pathbuf, filename);

if (send_tomtou)
- ima_add_violation(file, *pathname, iint,
+ ima_add_violation(ns, file, *pathname, iint,
"invalid_pcr", "ToMToU");
if (send_writers)
- ima_add_violation(file, *pathname, iint,
+ ima_add_violation(ns, file, *pathname, iint,
"invalid_pcr", "open_writers");
}

@@ -249,7 +250,7 @@ static int process_measurement(struct ima_namespace *ns,
}

if (!rc && violation_check)
- ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
+ ima_rdwr_violation_check(ns, file, iint, action & IMA_MEASURE,
&pathbuf, &pathname, filename);

inode_unlock(inode);
@@ -344,7 +345,7 @@ static int process_measurement(struct ima_namespace *ns,
pathname = ima_d_path(&file->f_path, &pathbuf, filename);

if (action & IMA_MEASURE)
- ima_store_measurement(iint, file, pathname,
+ ima_store_measurement(ns, iint, file, pathname,
xattr_value, xattr_len, modsig, pcr,
template_desc);
if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
@@ -987,7 +988,8 @@ int process_buffer_measurement(struct ima_namespace *ns,
goto out;
}

- ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr);
+ ret = ima_store_template(ns, entry, violation, NULL, event_data.buf,
+ pcr);
if (ret < 0) {
audit_cause = "store_entry";
ima_free_template_entry(entry);
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index 532da87ce519..43961d5cd2ef 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -31,13 +31,6 @@ static unsigned long binary_runtime_size;
static unsigned long binary_runtime_size = ULONG_MAX;
#endif

-/* key: inode (before secure-hashing a file) */
-struct ima_h_table ima_htable = {
- .len = ATOMIC_LONG_INIT(0),
- .violations = ATOMIC_LONG_INIT(0),
- .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
-};
-
/* mutex protects atomicity of extending measurement list
* and extending the TPM PCR aggregate. Since tpm_extend can take
* long (and the tpm driver uses a mutex), we can't use the spinlock.
@@ -45,8 +38,10 @@ struct ima_h_table ima_htable = {
static DEFINE_MUTEX(ima_extend_list_mutex);

/* lookup up the digest value in the hash table, and return the entry */
-static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,
- int pcr)
+static struct ima_queue_entry *ima_lookup_digest_entry
+ (struct ima_namespace *ns,
+ u8 *digest_value,
+ int pcr)
{
struct ima_queue_entry *qe, *ret = NULL;
unsigned int key;
@@ -54,7 +49,7 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,

key = ima_hash_key(digest_value);
rcu_read_lock();
- hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
+ hlist_for_each_entry_rcu(qe, &ns->ima_htable.queue[key], hnext) {
rc = memcmp(qe->entry->digests[ima_hash_algo_idx].digest,
digest_value, hash_digest_size[ima_hash_algo]);
if ((rc == 0) && (qe->entry->pcr == pcr)) {
@@ -90,7 +85,8 @@ static int get_binary_runtime_size(struct ima_template_entry *entry)
*
* (Called with ima_extend_list_mutex held.)
*/
-static int ima_add_digest_entry(struct ima_template_entry *entry,
+static int ima_add_digest_entry(struct ima_namespace *ns,
+ struct ima_template_entry *entry,
bool update_htable)
{
struct ima_queue_entry *qe;
@@ -106,10 +102,12 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
INIT_LIST_HEAD(&qe->later);
list_add_tail_rcu(&qe->later, &ima_measurements);

- atomic_long_inc(&ima_htable.len);
+ atomic_long_inc(&ns->ima_htable.len);
if (update_htable) {
key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest);
- hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
+ hlist_add_head_rcu(&qe->hnext, &ns->ima_htable.queue[key]);
+ } else {
+ INIT_HLIST_NODE(&qe->hnext);
}

if (binary_runtime_size != ULONG_MAX) {
@@ -156,7 +154,8 @@ static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr)
* kexec, maintain the total memory size required for serializing the
* binary_runtime_measurements.
*/
-int ima_add_template_entry(struct ima_template_entry *entry, int violation,
+int ima_add_template_entry(struct ima_namespace *ns,
+ struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode,
const unsigned char *filename)
{
@@ -169,14 +168,14 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,

mutex_lock(&ima_extend_list_mutex);
if (!violation && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE)) {
- if (ima_lookup_digest_entry(digest, entry->pcr)) {
+ if (ima_lookup_digest_entry(ns, digest, entry->pcr)) {
audit_cause = "hash_exists";
result = -EEXIST;
goto out;
}
}

- result = ima_add_digest_entry(entry,
+ result = ima_add_digest_entry(ns, entry,
!IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE));
if (result < 0) {
audit_cause = "ENOMEM";
@@ -201,12 +200,13 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
return result;
}

-int ima_restore_measurement_entry(struct ima_template_entry *entry)
+int ima_restore_measurement_entry(struct ima_namespace *ns,
+ struct ima_template_entry *entry)
{
int result = 0;

mutex_lock(&ima_extend_list_mutex);
- result = ima_add_digest_entry(entry, 0);
+ result = ima_add_digest_entry(ns, entry, 0);
mutex_unlock(&ima_extend_list_mutex);
return result;
}
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index db1ad6d7a57f..e5c33a3f0296 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -404,7 +404,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc,
}

/* Restore the serialized binary measurement list without extending PCRs. */
-int ima_restore_measurement_list(loff_t size, void *buf)
+int ima_restore_measurement_list(struct ima_namespace *ns,
+ loff_t size, void *buf)
{
char template_name[MAX_TEMPLATE_NAME_LEN];
unsigned char zero[TPM_DIGEST_SIZE] = { 0 };
@@ -520,7 +521,7 @@ int ima_restore_measurement_list(loff_t size, void *buf)

entry->pcr = !ima_canonical_fmt ? *(u32 *)(hdr[HDR_PCR].data) :
le32_to_cpu(*(__le32 *)(hdr[HDR_PCR].data));
- ret = ima_restore_measurement_entry(entry);
+ ret = ima_restore_measurement_entry(ns, entry);
if (ret < 0)
break;

--
2.34.1