lsm: [[subj_user=] [subj_role=] [subj_type=]
[obj_user=] [obj_role=] [obj_type=]]
option: [[appraise_type=]] [template=] [permit_directio]
- [appraise_flag=] [keyrings=]
+ [appraise_flag=] [appraise_algos=] [keyrings=]
base:
func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK]
- [FIRMWARE_CHECK]
+ [FIRMWARE_CHECK]
[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
[KEXEC_CMDLINE] [KEY_CHECK] [CRITICAL_DATA]
+ [SETXATTR_CHECK]
mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
[[^]MAY_EXEC]
fsmagic:= hex value
label:= [selinux]|[kernel_info]|[data_label]
data_label:= a unique string used for grouping and limiting critical data.
For example, "selinux" to measure critical data for SELinux.
+ appraise_algos:= comma-separated list of hash algorithms
+ For example, "sha256,sha512" to only accept to appraise
+ files where the security.ima xattr was hashed with one
+ of these two algorithms.
default policy:
# PROC_SUPER_MAGIC
keys added to .builtin_trusted_keys or .ima keyring:
measure func=KEY_CHECK keyrings=.builtin_trusted_keys|.ima
+
+ Example of the special SETXATTR_CHECK appraise rule, that
+ restricts the hash algorithms allowed when writing to the
+ security.ima xattr of a file:
+
+ appraise func=SETXATTR_CHECK appraise_algos=sha256,sha384,sha512
if (noio)
noio_flag = memalloc_noio_save();
- ima_measure_critical_data(DM_NAME, event_name, buf, buf_len, false);
+ ima_measure_critical_data(DM_NAME, event_name, buf, buf_len,
+ false, NULL, 0);
if (noio)
memalloc_noio_restore(noio_flag);
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
+#include <crypto/hash_info.h>
struct linux_binprm;
#ifdef CONFIG_IMA
+extern enum hash_algo ima_get_current_hash_algo(void);
extern int ima_bprm_check(struct linux_binprm *bprm);
extern int ima_file_check(struct file *file, int mask);
extern void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
-extern void ima_measure_critical_data(const char *event_label,
- const char *event_name,
- const void *buf, size_t buf_len,
- bool hash);
+extern int ima_measure_critical_data(const char *event_label,
+ const char *event_name,
+ const void *buf, size_t buf_len,
+ bool hash, u8 *digest, size_t digest_len);
#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM
extern void ima_appraise_parse_cmdline(void);
#endif
#else
+static inline enum hash_algo ima_get_current_hash_algo(void)
+{
+ return HASH_ALGO__LAST;
+}
+
static inline int ima_bprm_check(struct linux_binprm *bprm)
{
return 0;
static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {}
-static inline void ima_measure_critical_data(const char *event_label,
+static inline int ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
- bool hash) {}
+ bool hash, u8 *digest,
+ size_t digest_len)
+{
+ return -ENOENT;
+}
#endif /* CONFIG_IMA */
select SECURITYFS
select CRYPTO
select CRYPTO_HMAC
- select CRYPTO_MD5
select CRYPTO_SHA1
select CRYPTO_HASH_INFO
select TCG_TPM if HAS_IOMEM && !UML
/* current content of the policy */
extern int ima_policy_flag;
+/* bitset of digests algorithms allowed in the setxattr hook */
+extern atomic_t ima_setxattr_allowed_hash_algorithms;
+
/* set during initialization */
-extern int ima_hash_algo;
+extern int ima_hash_algo __ro_after_init;
extern int ima_sha1_idx __ro_after_init;
extern int ima_hash_algo_idx __ro_after_init;
extern int ima_extra_slots __ro_after_init;
hook(KEXEC_CMDLINE, kexec_cmdline) \
hook(KEY_CHECK, key) \
hook(CRITICAL_DATA, critical_data) \
+ hook(SETXATTR_CHECK, setxattr_check) \
hook(MAX_CHECK, none)
#define __ima_hook_enumify(ENUM, str) ENUM,
const struct cred *cred, u32 secid, int mask,
enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
- const char *func_data);
+ const char *func_data, unsigned int *allowed_algos);
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,
struct evm_ima_xattr_data *xattr_value,
int xattr_len, const struct modsig *modsig, int pcr,
struct ima_template_desc *template_desc);
-void process_buffer_measurement(struct user_namespace *mnt_userns,
- struct inode *inode, const void *buf, int size,
- const char *eventname, enum ima_hooks func,
- int pcr, const char *func_data,
- bool buf_hash);
+int process_buffer_measurement(struct user_namespace *mnt_userns,
+ struct inode *inode, const void *buf, int size,
+ const char *eventname, enum ima_hooks func,
+ int pcr, const char *func_data,
+ bool buf_hash, u8 *digest, size_t digest_len);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
const struct cred *cred, u32 secid, enum ima_hooks func,
int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
- const char *func_data);
+ const char *func_data, unsigned int *allowed_algos);
void ima_init_policy(void);
void ima_update_policy(void);
-void ima_update_policy_flag(void);
+void ima_update_policy_flags(void);
ssize_t ima_parse_add_rule(char *);
void ima_delete_rules(void);
int ima_check_policy(void);
void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
enum ima_hooks func);
-enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
+enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value,
int xattr_len);
int ima_read_xattr(struct dentry *dentry,
struct evm_ima_xattr_data **xattr_value);
* @pcr: pointer filled in if matched measure policy sets pcr=
* @template_desc: pointer filled in if matched measure policy sets template=
* @func_data: func specific data, may be NULL
+ * @allowed_algos: allowlist of hash algorithms for the IMA xattr
*
* The policy is defined in terms of keypairs:
* subj=, obj=, type=, func=, mask=, fsmagic=
const struct cred *cred, u32 secid, int mask,
enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
- const char *func_data)
+ const char *func_data, unsigned int *allowed_algos)
{
int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
flags &= ima_policy_flag;
return ima_match_policy(mnt_userns, inode, cred, secid, func, mask,
- flags, pcr, template_desc, func_data);
+ flags, pcr, template_desc, func_data,
+ allowed_algos);
}
/*
return 0;
security_task_getsecid_subj(current, &secid);
- return ima_match_policy(mnt_userns, inode, current_cred(), secid, func,
- mask, IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
+ return ima_match_policy(mnt_userns, inode, current_cred(), secid,
+ func, mask, IMA_APPRAISE | IMA_HASH, NULL,
+ NULL, NULL, NULL);
}
static int ima_fix_xattr(struct dentry *dentry,
}
}
-enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
+enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value,
int xattr_len)
{
struct signature_v2_hdr *sig;
switch (xattr_value->type) {
case EVM_IMA_XATTR_DIGSIG:
sig = (typeof(sig))xattr_value;
- if (sig->version != 2 || xattr_len <= sizeof(*sig))
+ if (sig->version != 2 || xattr_len <= sizeof(*sig)
+ || sig->hash_algo >= HASH_ALGO__LAST)
return ima_hash_algo;
return sig->hash_algo;
break;
if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
process_buffer_measurement(&init_user_ns, NULL, digest, digestsize,
"blacklisted-hash", NONE,
- pcr, NULL, false);
+ pcr, NULL, false, NULL, 0);
}
return rc;
clear_bit(IMA_DIGSIG, &iint->atomic_flags);
}
+/**
+ * validate_hash_algo() - Block setxattr with unsupported hash algorithms
+ * @dentry: object of the setxattr()
+ * @xattr_value: userland supplied xattr value
+ * @xattr_value_len: length of xattr_value
+ *
+ * The xattr value is mapped to its hash algorithm, and this algorithm
+ * must be built in the kernel for the setxattr to be allowed.
+ *
+ * Emit an audit message when the algorithm is invalid.
+ *
+ * Return: 0 on success, else an error.
+ */
+static int validate_hash_algo(struct dentry *dentry,
+ const struct evm_ima_xattr_data *xattr_value,
+ size_t xattr_value_len)
+{
+ char *path = NULL, *pathbuf = NULL;
+ enum hash_algo xattr_hash_algo;
+ const char *errmsg = "unavailable-hash-algorithm";
+ unsigned int allowed_hashes;
+
+ xattr_hash_algo = ima_get_hash_algo(xattr_value, xattr_value_len);
+
+ allowed_hashes = atomic_read(&ima_setxattr_allowed_hash_algorithms);
+
+ if (allowed_hashes) {
+ /* success if the algorithm is allowed in the ima policy */
+ if (allowed_hashes & (1U << xattr_hash_algo))
+ return 0;
+
+ /*
+ * We use a different audit message when the hash algorithm
+ * is denied by a policy rule, instead of not being built
+ * in the kernel image
+ */
+ errmsg = "denied-hash-algorithm";
+ } else {
+ if (likely(xattr_hash_algo == ima_hash_algo))
+ return 0;
+
+ /* allow any xattr using an algorithm built in the kernel */
+ if (crypto_has_alg(hash_algo_name[xattr_hash_algo], 0, 0))
+ return 0;
+ }
+
+ pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
+ if (!pathbuf)
+ return -EACCES;
+
+ path = dentry_path(dentry, pathbuf, PATH_MAX);
+
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, d_inode(dentry), path,
+ "set_data", errmsg, -EACCES, 0);
+
+ kfree(pathbuf);
+
+ return -EACCES;
+}
+
int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
const void *xattr_value, size_t xattr_value_len)
{
digsig = (xvalue->type == EVM_XATTR_PORTABLE_DIGSIG);
}
if (result == 1 || evm_revalidate_status(xattr_name)) {
+ result = validate_hash_algo(dentry, xvalue, xattr_value_len);
+ if (result)
+ return result;
+
ima_reset_appraise_flags(d_backing_inode(dentry), digsig);
- if (result == 1)
- result = 0;
}
return result;
}
*/
process_buffer_measurement(&init_user_ns, NULL, payload, payload_len,
keyring->description, KEY_CHECK, 0,
- keyring->description, false);
+ keyring->description, false, NULL, 0);
}
ima_init_key_queue();
ima_measure_critical_data("kernel_info", "kernel_version",
- UTS_RELEASE, strlen(UTS_RELEASE), false);
+ UTS_RELEASE, strlen(UTS_RELEASE), false,
+ NULL, 0);
return rc;
}
int ima_appraise;
#endif
-int ima_hash_algo = HASH_ALGO_SHA1;
+int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1;
static int hash_setup_done;
static struct notifier_block ima_lsm_policy_notifier = {
}
__setup("ima_hash=", hash_setup);
+enum hash_algo ima_get_current_hash_algo(void)
+{
+ return ima_hash_algo;
+}
+
/* 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,
int xattr_len = 0;
bool violation_check;
enum hash_algo hash_algo;
+ unsigned int allowed_algos = 0;
if (!ima_policy_flag || !S_ISREG(inode->i_mode))
return 0;
* Included is the appraise submask.
*/
action = ima_get_action(file_mnt_user_ns(file), inode, cred, secid,
- mask, func, &pcr, &template_desc, NULL);
+ mask, func, &pcr, &template_desc, NULL,
+ &allowed_algos);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
if (!action && !violation_check)
if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
rc = 0;
+
+ /* Ensure the digest was generated using an allowed algorithm */
+ if (rc == 0 && must_appraise && allowed_algos != 0 &&
+ (allowed_algos & (1U << hash_algo)) == 0) {
+ rc = -EACCES;
+
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, file_inode(file),
+ pathname, "collect_data",
+ "denied-hash-algorithm", rc, 0);
+ }
out_locked:
if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
!(iint->flags & IMA_NEW_FILE))
inode = file_inode(vma->vm_file);
action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
current_cred(), secid, MAY_EXEC, MMAP_CHECK,
- &pcr, &template, NULL);
+ &pcr, &template, NULL, NULL);
/* Is the mmap'ed file in policy? */
if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
return 0;
}
-/*
+/**
* process_buffer_measurement - Measure the buffer or the buffer data hash
* @mnt_userns: user namespace of the mount the inode was found from
* @inode: inode associated with the object being measured (NULL for KEY_CHECK)
* @pcr: pcr to extend the measurement
* @func_data: func specific data, may be NULL
* @buf_hash: measure buffer data hash
+ * @digest: buffer digest will be written to
+ * @digest_len: buffer length
*
* Based on policy, either the buffer data or buffer data hash is measured
+ *
+ * Return: 0 if the buffer has been successfully measured, 1 if the digest
+ * has been written to the passed location but not added to a measurement entry,
+ * a negative value otherwise.
*/
-void process_buffer_measurement(struct user_namespace *mnt_userns,
- struct inode *inode, const void *buf, int size,
- const char *eventname, enum ima_hooks func,
- int pcr, const char *func_data,
- bool buf_hash)
+int process_buffer_measurement(struct user_namespace *mnt_userns,
+ struct inode *inode, const void *buf, int size,
+ const char *eventname, enum ima_hooks func,
+ int pcr, const char *func_data,
+ bool buf_hash, u8 *digest, size_t digest_len)
{
int ret = 0;
const char *audit_cause = "ENOMEM";
int action = 0;
u32 secid;
- if (!ima_policy_flag)
- return;
+ if (digest && digest_len < digest_hash_len)
+ return -EINVAL;
+
+ if (!ima_policy_flag && !digest)
+ return -ENOENT;
template = ima_template_desc_buf();
if (!template) {
security_task_getsecid_subj(current, &secid);
action = ima_get_action(mnt_userns, inode, current_cred(),
secid, 0, func, &pcr, &template,
- func_data);
- if (!(action & IMA_MEASURE))
- return;
+ func_data, NULL);
+ if (!(action & IMA_MEASURE) && !digest)
+ return -ENOENT;
}
if (!pcr)
event_data.buf_len = digest_hash_len;
}
+ if (digest)
+ memcpy(digest, iint.ima_hash->digest, digest_hash_len);
+
+ if (!ima_policy_flag || (func && !(action & IMA_MEASURE)))
+ return 1;
+
ret = ima_alloc_init_template(&event_data, &entry, template);
if (ret < 0) {
audit_cause = "alloc_entry";
func_measure_str(func),
audit_cause, ret, 0, ret);
- return;
+ return ret;
}
/**
process_buffer_measurement(file_mnt_user_ns(f.file), file_inode(f.file),
buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
- NULL, false);
+ NULL, false, NULL, 0);
fdput(f);
}
* @buf: pointer to buffer data
* @buf_len: length of buffer data (in bytes)
* @hash: measure buffer data hash
+ * @digest: buffer digest will be written to
+ * @digest_len: buffer length
*
* Measure data critical to the integrity of the kernel into the IMA log
* and extend the pcr. Examples of critical data could be various data
* structures, policies, and states stored in kernel memory that can
* impact the integrity of the system.
+ *
+ * Return: 0 if the buffer has been successfully measured, 1 if the digest
+ * has been written to the passed location but not added to a measurement entry,
+ * a negative value otherwise.
*/
-void ima_measure_critical_data(const char *event_label,
- const char *event_name,
- const void *buf, size_t buf_len,
- bool hash)
+int ima_measure_critical_data(const char *event_label,
+ const char *event_name,
+ const void *buf, size_t buf_len,
+ bool hash, u8 *digest, size_t digest_len)
{
if (!event_name || !event_label || !buf || !buf_len)
- return;
+ return -ENOPARAM;
- process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name,
- CRITICAL_DATA, 0, event_label,
- hash);
+ return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len,
+ event_name, CRITICAL_DATA, 0,
+ event_label, hash, digest,
+ digest_len);
}
EXPORT_SYMBOL_GPL(ima_measure_critical_data);
pr_warn("Couldn't register LSM notifier, error %d\n", error);
if (!error)
- ima_update_policy_flag();
+ ima_update_policy_flags();
return error;
}
/*
* Allocate the IMA blacklist keyring
*/
-__init int ima_mok_init(void)
+static __init int ima_mok_init(void)
{
struct key_restriction *restriction;
#define IMA_FSNAME 0x0200
#define IMA_KEYRINGS 0x0400
#define IMA_LABEL 0x0800
+#define IMA_VALIDATE_ALGOS 0x1000
#define UNKNOWN 0
#define MEASURE 0x0001 /* same as IMA_MEASURE */
static int temp_ima_appraise;
static int build_ima_appraise __ro_after_init;
+atomic_t ima_setxattr_allowed_hash_algorithms;
+
#define MAX_LSM_RULES 6
enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
bool (*uid_op)(kuid_t, kuid_t); /* Handlers for operators */
bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
int pcr;
+ unsigned int allowed_algos; /* bitfield of allowed hash algorithms */
struct {
void *rule; /* LSM file metadata specific */
char *args_p; /* audit value */
struct ima_template_desc *template;
};
+/*
+ * sanity check in case the kernels gains more hash algorithms that can
+ * fit in an unsigned int
+ */
+static_assert(
+ 8 * sizeof(unsigned int) >= HASH_ALGO__LAST,
+ "The bitfield allowed_algos in ima_rule_entry is too small to contain all the supported hash algorithms, consider using a bigger type");
+
/*
* Without LSM specific knowledge, the default policy can only be
* written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
* @pcr: set the pcr to extend
* @template_desc: the template that should be used for this rule
* @func_data: func specific data, may be NULL
+ * @allowed_algos: allowlist of hash algorithms for the IMA xattr
*
* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
* conditions.
const struct cred *cred, u32 secid, enum ima_hooks func,
int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
- const char *func_data)
+ const char *func_data, unsigned int *allowed_algos)
{
struct ima_rule_entry *entry;
int action = 0, actmask = flags | (flags << 1);
action &= ~IMA_HASH;
if (ima_fail_unverifiable_sigs)
action |= IMA_FAIL_UNVERIFIABLE_SIGS;
- }
+ if (allowed_algos &&
+ entry->flags & IMA_VALIDATE_ALGOS)
+ *allowed_algos = entry->allowed_algos;
+ }
if (entry->action & IMA_DO_MASK)
actmask &= ~(entry->action | entry->action << 1);
return action;
}
-/*
- * Initialize the ima_policy_flag variable based on the currently
- * loaded policy. Based on this flag, the decision to short circuit
- * out of a function or not call the function in the first place
- * can be made earlier.
+/**
+ * ima_update_policy_flags() - Update global IMA variables
+ *
+ * Update ima_policy_flag and ima_setxattr_allowed_hash_algorithms
+ * based on the currently loaded policy.
+ *
+ * With ima_policy_flag, the decision to short circuit out of a function
+ * or not call the function in the first place can be made earlier.
+ *
+ * With ima_setxattr_allowed_hash_algorithms, the policy can restrict the
+ * set of hash algorithms accepted when updating the security.ima xattr of
+ * a file.
+ *
+ * Context: called after a policy update and at system initialization.
*/
-void ima_update_policy_flag(void)
+void ima_update_policy_flags(void)
{
struct ima_rule_entry *entry;
+ int new_policy_flag = 0;
+ rcu_read_lock();
list_for_each_entry(entry, ima_rules, list) {
+ /*
+ * SETXATTR_CHECK rules do not implement a full policy check
+ * because rule checking would probably have an important
+ * performance impact on setxattr(). As a consequence, only one
+ * SETXATTR_CHECK can be active at a given time.
+ * Because we want to preserve that property, we set out to use
+ * atomic_cmpxchg. Either:
+ * - the atomic was non-zero: a setxattr hash policy is
+ * already enforced, we do nothing
+ * - the atomic was zero: no setxattr policy was set, enable
+ * the setxattr hash policy
+ */
+ if (entry->func == SETXATTR_CHECK) {
+ atomic_cmpxchg(&ima_setxattr_allowed_hash_algorithms,
+ 0, entry->allowed_algos);
+ /* SETXATTR_CHECK doesn't impact ima_policy_flag */
+ continue;
+ }
+
if (entry->action & IMA_DO_MASK)
- ima_policy_flag |= entry->action;
+ new_policy_flag |= entry->action;
}
+ rcu_read_unlock();
ima_appraise |= (build_ima_appraise | temp_ima_appraise);
if (!ima_appraise)
- ima_policy_flag &= ~IMA_APPRAISE;
+ new_policy_flag &= ~IMA_APPRAISE;
+
+ ima_policy_flag = new_policy_flag;
}
static int ima_appraise_flag(enum ima_hooks func)
ARRAY_SIZE(critical_data_rules),
IMA_DEFAULT_POLICY);
- ima_update_policy_flag();
+ atomic_set(&ima_setxattr_allowed_hash_algorithms, 0);
+
+ ima_update_policy_flags();
}
/* Make sure we have a valid policy, at least containing some rules. */
*/
kfree(arch_policy_entry);
}
- ima_update_policy_flag();
+ ima_update_policy_flags();
/* Custom IMA policy has been loaded */
ima_process_queued_keys();
Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq,
Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
- Opt_appraise_type, Opt_appraise_flag,
+ Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos,
Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
Opt_label, Opt_err
};
{Opt_fowner_lt, "fowner<%s"},
{Opt_appraise_type, "appraise_type=%s"},
{Opt_appraise_flag, "appraise_flag=%s"},
+ {Opt_appraise_algos, "appraise_algos=%s"},
{Opt_permit_directio, "permit_directio"},
{Opt_pcr, "pcr=%s"},
{Opt_template, "template=%s"},
return false;
if (entry->action != APPRAISE &&
- entry->flags & (IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED | IMA_CHECK_BLACKLIST))
+ entry->flags & (IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED |
+ IMA_CHECK_BLACKLIST | IMA_VALIDATE_ALGOS))
return false;
/*
IMA_UID | IMA_FOWNER | IMA_FSUUID |
IMA_INMASK | IMA_EUID | IMA_PCR |
IMA_FSNAME | IMA_DIGSIG_REQUIRED |
- IMA_PERMIT_DIRECTIO))
+ IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS))
return false;
break;
IMA_INMASK | IMA_EUID | IMA_PCR |
IMA_FSNAME | IMA_DIGSIG_REQUIRED |
IMA_PERMIT_DIRECTIO | IMA_MODSIG_ALLOWED |
- IMA_CHECK_BLACKLIST))
+ IMA_CHECK_BLACKLIST | IMA_VALIDATE_ALGOS))
return false;
break;
if (ima_rule_contains_lsm_cond(entry))
return false;
+ break;
+ case SETXATTR_CHECK:
+ /* any action other than APPRAISE is unsupported */
+ if (entry->action != APPRAISE)
+ return false;
+
+ /* SETXATTR_CHECK requires an appraise_algos parameter */
+ if (!(entry->flags & IMA_VALIDATE_ALGOS))
+ return false;
+
+ /*
+ * full policies are not supported, they would have too
+ * much of a performance impact
+ */
+ if (entry->flags & ~(IMA_FUNC | IMA_VALIDATE_ALGOS))
+ return false;
+
break;
default:
return false;
return true;
}
+static unsigned int ima_parse_appraise_algos(char *arg)
+{
+ unsigned int res = 0;
+ int idx;
+ char *token;
+
+ while ((token = strsep(&arg, ",")) != NULL) {
+ idx = match_string(hash_algo_name, HASH_ALGO__LAST, token);
+
+ if (idx < 0) {
+ pr_err("unknown hash algorithm \"%s\"",
+ token);
+ return 0;
+ }
+
+ if (!crypto_has_alg(hash_algo_name[idx], 0, 0)) {
+ pr_err("unavailable hash algorithm \"%s\", check your kernel configuration",
+ token);
+ return 0;
+ }
+
+ /* Add the hash algorithm to the 'allowed' bitfield */
+ res |= (1U << idx);
+ }
+
+ return res;
+}
+
static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
{
struct audit_buffer *ab;
entry->func = KEY_CHECK;
else if (strcmp(args[0].from, "CRITICAL_DATA") == 0)
entry->func = CRITICAL_DATA;
+ else if (strcmp(args[0].from, "SETXATTR_CHECK") == 0)
+ entry->func = SETXATTR_CHECK;
else
result = -EINVAL;
if (!result)
else
result = -EINVAL;
break;
+ case Opt_appraise_algos:
+ ima_log_string(ab, "appraise_algos", args[0].from);
+
+ if (entry->allowed_algos) {
+ result = -EINVAL;
+ break;
+ }
+
+ entry->allowed_algos =
+ ima_parse_appraise_algos(args[0].from);
+ /* invalid or empty list of algorithms */
+ if (!entry->allowed_algos) {
+ result = -EINVAL;
+ break;
+ }
+
+ entry->flags |= IMA_VALIDATE_ALGOS;
+
+ break;
case Opt_permit_directio:
entry->flags |= IMA_PERMIT_DIRECTIO;
break;
seq_printf(m, "%s%s", i ? "|" : "", opt_list->items[i]);
}
+static void ima_policy_show_appraise_algos(struct seq_file *m,
+ unsigned int allowed_hashes)
+{
+ int idx, list_size = 0;
+
+ for (idx = 0; idx < HASH_ALGO__LAST; idx++) {
+ if (!(allowed_hashes & (1U << idx)))
+ continue;
+
+ /* only add commas if the list contains multiple entries */
+ if (list_size++)
+ seq_puts(m, ",");
+
+ seq_puts(m, hash_algo_name[idx]);
+ }
+}
+
int ima_policy_show(struct seq_file *m, void *v)
{
struct ima_rule_entry *entry = v;
seq_puts(m, " ");
}
+ if (entry->flags & IMA_VALIDATE_ALGOS) {
+ seq_puts(m, "appraise_algos=");
+ ima_policy_show_appraise_algos(m, entry->allowed_algos);
+ seq_puts(m, " ");
+ }
+
for (i = 0; i < MAX_LSM_RULES; i++) {
if (entry->lsm[i].rule) {
switch (i) {
entry->keyring_name,
KEY_CHECK, 0,
entry->keyring_name,
- false);
+ false, NULL, 0);
list_del(&entry->list);
ima_free_key_entry(entry);
}
}
ima_measure_critical_data("selinux", "selinux-state",
- state_str, strlen(state_str), false);
+ state_str, strlen(state_str), false,
+ NULL, 0);
kfree(state_str);
}
ima_measure_critical_data("selinux", "selinux-policy-hash",
- policy, policy_len, true);
+ policy, policy_len, true,
+ NULL, 0);
vfree(policy);
}
projects / linux-2.6-microblaze.git / commitdiff