[RFC,v2,07/19] ima: Move ima_htable into ima_namespace

Message ID	20211203023118.1447229-8-stefanb@linux.ibm.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> From: Stefan Berger <stefanb@linux.ibm.com> To: linux-integrity@vger.kernel.org Cc: zohar@linux.ibm.com, serge@hallyn.com, christian.brauner@ubuntu.com, containers@lists.linux.dev, dmitry.kasatkin@gmail.com, ebiederm@xmission.com, krzysztof.struczynski@huawei.com, roberto.sassu@huawei.com, mpeters@redhat.com, lhinds@redhat.com, lsturman@redhat.com, puiterwi@redhat.com, jejb@linux.ibm.com, jamjoom@us.ibm.com, linux-kernel@vger.kernel.org, paul@paul-moore.com, rgb@redhat.com, linux-security-module@vger.kernel.org, jmorris@namei.org, Stefan Berger <stefanb@linux.ibm.com> Subject: [RFC v2 07/19] ima: Move ima_htable into ima_namespace Date: Thu, 2 Dec 2021 21:31:06 -0500 Message-Id: <20211203023118.1447229-8-stefanb@linux.ibm.com> In-Reply-To: <20211203023118.1447229-1-stefanb@linux.ibm.com> References: <20211203023118.1447229-1-stefanb@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	ima: Namespace IMA with audit support in IMA-ns \| expand [RFC,v2,00/19] ima: Namespace IMA with audit support in IMA-ns [RFC,v2,01/19] ima: Add IMA namespace support [RFC,v2,02/19] ima: Define ns_status for storing namespaced iint data [RFC,v2,03/19] ima: Namespace audit status flags [RFC,v2,04/19] ima: Move delayed work queue and variables into ima_namespace [RFC,v2,05/19] ima: Move IMA's keys queue related variables into ima_namespace [RFC,v2,06/19] ima: Move policy related variables into ima_namespace [RFC,v2,07/19] ima: Move ima_htable into ima_namespace [RFC,v2,08/19] ima: Move measurement list related variables into ima_namespace [RFC,v2,09/19] ima: Only accept AUDIT rules for IMA non-init_ima_ns namespaces for now [RFC,v2,10/19] ima: Implement hierarchical processing of file accesses [RFC,v2,11/19] securityfs: Prefix global variables with securityfs_ [RFC,v2,12/19] securityfs: Pass static variables as parameters from top level functions [RFC,v2,13/19] securityfs: Extend securityfs with namespacing support [RFC,v2,14/19] ima: Move some IMA policy and filesystem related variables into ima_namespace [RFC,v2,15/19] capabilities: Introduce CAP_INTEGRITY_ADMIN [RFC,v2,16/19] ima: Use integrity_admin_ns_capable() to check corresponding capability [RFC,v2,17/19] userns: Introduce a refcount variable for calling early teardown function [RFC,v2,18/19] ima/userns: Define early teardown function for IMA namespace [RFC,v2,19/19] ima: Setup securityfs for IMA namespace

diff --git a/include/linux/ima.h b/include/linux/ima.h index e13e63a539d8..929bf87b1bbf 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -211,6 +211,15 @@ static inline int ima_inode_removexattr(struct dentry *dentry, } #endif /* CONFIG_IMA_APPRAISE */ +#define IMA_HASH_BITS 10 +#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS) + +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 { struct kref kref; struct user_namespace *user_ns; @@ -248,6 +257,8 @@ struct ima_namespace { struct list_head __rcu *ima_rules; /* current content of the policy */ int ima_policy_flag; + + struct ima_h_table ima_htable; }; extern struct ima_namespace init_ima_ns; diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e295141f2478..a7e6c8fb152a 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -32,9 +32,6 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 }; #define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE #define IMA_EVENT_NAME_LEN_MAX 255 -#define IMA_HASH_BITS 10 -#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS) - #define IMA_TEMPLATE_FIELD_ID_MAX_LEN 16 #define IMA_TEMPLATE_NUM_FIELDS_MAX 15 @@ -143,7 +140,8 @@ struct ns_status { /* Internal IMA function definitions */ int ima_init(void); int ima_fs_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); @@ -152,7 +150,8 @@ 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); @@ -165,8 +164,10 @@ 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); @@ -180,19 +181,6 @@ 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 */ - return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE; -} - #define __ima_hooks(hook) \ hook(NONE, none) \ hook(FILE_CHECK, file) \ @@ -272,7 +260,8 @@ 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, @@ -289,7 +278,8 @@ 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 808aec56dbb6..71c5517fe8bc 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -100,7 +100,8 @@ 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) { @@ -120,7 +121,7 @@ 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; } @@ -131,7 +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) { @@ -145,14 +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); @@ -299,7 +301,8 @@ 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, @@ -334,7 +337,7 @@ 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 fc0413c8c358..9df8648ad64d 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -53,7 +53,9 @@ 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 = get_current_ns(); + + return ima_show_htable_value(buf, count, ppos, &ns->ima_htable.violations); } static const struct file_operations ima_htable_violations_ops = { @@ -65,8 +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 = get_current_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 2ec9a22bbddf..6104d5116a7f 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"; @@ -86,7 +86,7 @@ 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) { @@ -145,7 +145,7 @@ 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 */ + rc = ima_add_boot_aggregate(&init_ima_ns); /* boot aggregate must be first entry */ 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 2d644791a795..e13adc3287ed 100644 --- a/security/integrity/ima/ima_init_ima_ns.c +++ b/security/integrity/ima/ima_init_ima_ns.c @@ -40,6 +40,10 @@ int ima_init_namespace(struct ima_namespace *ns) ns->ima_rules = (struct list_head __rcu *)(&ns->ima_default_rules); ns->ima_policy_flag = 0; + 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_main.c b/security/integrity/ima/ima_main.c index 9cf1fd7c70bf..d692c9d53a98 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"); } @@ -256,7 +257,7 @@ 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); @@ -353,7 +354,7 @@ 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)) { @@ -969,7 +970,7 @@ 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..373154039b91 100644 --- a/security/integrity/ima/ima_queue.c +++ b/security/integrity/ima/ima_queue.c @@ -17,6 +17,7 @@ #include <linux/rculist.h> #include <linux/slab.h> +#include <linux/ima.h> #include "ima.h" #define AUDIT_CAUSE_LEN_MAX 32 @@ -31,21 +32,22 @@ 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. */ static DEFINE_MUTEX(ima_extend_list_mutex); + +static inline unsigned int ima_hash_key(u8 *digest) +{ + /* there is no point in taking a hash of part of a digest */ + return (digest[0] | digest[1] << 8) % IMA_MEASURE_HTABLE_SIZE; +} + /* 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, +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; @@ -54,7 +56,7 @@ 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 +92,8 @@ 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; @@ -106,11 +109,12 @@ 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) { int size; @@ -156,7 +160,8 @@ 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 +174,14 @@ 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 +206,13 @@ 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 694560396be0..2ae87eb23a59 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -400,7 +400,7 @@ 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 }; @@ -516,7 +516,7 @@ 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;

[RFC,v2,07/19] ima: Move ima_htable into ima_namespace

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