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

Serge E. Hallyn
2022-05-21T02:50:06Z

On Wed, Apr 20, 2022 at 10:06:12AM -0400, Stefan Berger wrote:
> 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>

Reviewed-by: Serge Hallyn <serge@hallyn.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