diff options
Diffstat (limited to 'security/integrity/ima/ima_main.c')
-rw-r--r-- | security/integrity/ima/ima_main.c | 123 |
1 files changed, 65 insertions, 58 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 2917f980bf30..62f59eca32d3 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -77,42 +77,39 @@ __setup("ima_hash=", hash_setup); * could result in a file measurement error. * */ -static void ima_rdwr_violation_check(struct file *file) +static void ima_rdwr_violation_check(struct file *file, + struct integrity_iint_cache *iint, + int must_measure, + char **pathbuf, + const char **pathname) { struct inode *inode = file_inode(file); fmode_t mode = file->f_mode; bool send_tomtou = false, send_writers = false; - char *pathbuf = NULL; - const char *pathname; - - if (!S_ISREG(inode->i_mode) || !ima_initialized) - return; if (mode & FMODE_WRITE) { if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { - struct integrity_iint_cache *iint; - iint = integrity_iint_find(inode); + if (!iint) + iint = integrity_iint_find(inode); /* IMA_MEASURE is set from reader side */ if (iint && (iint->flags & IMA_MEASURE)) send_tomtou = true; } } else { - if ((atomic_read(&inode->i_writecount) > 0) && - ima_must_measure(inode, MAY_READ, FILE_CHECK)) + if ((atomic_read(&inode->i_writecount) > 0) && must_measure) send_writers = true; } if (!send_tomtou && !send_writers) return; - pathname = ima_d_path(&file->f_path, &pathbuf); + *pathname = ima_d_path(&file->f_path, pathbuf); if (send_tomtou) - ima_add_violation(file, pathname, "invalid_pcr", "ToMToU"); + ima_add_violation(file, *pathname, "invalid_pcr", "ToMToU"); if (send_writers) - ima_add_violation(file, pathname, + ima_add_violation(file, *pathname, "invalid_pcr", "open_writers"); - kfree(pathbuf); } static void ima_check_last_writer(struct integrity_iint_cache *iint, @@ -124,11 +121,13 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint, return; mutex_lock(&inode->i_mutex); - if (atomic_read(&inode->i_writecount) == 1 && - iint->version != inode->i_version) { - iint->flags &= ~IMA_DONE_MASK; - if (iint->flags & IMA_APPRAISE) - ima_update_xattr(iint, file); + if (atomic_read(&inode->i_writecount) == 1) { + if ((iint->version != inode->i_version) || + (iint->flags & IMA_NEW_FILE)) { + iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); + if (iint->flags & IMA_APPRAISE) + ima_update_xattr(iint, file); + } } mutex_unlock(&inode->i_mutex); } @@ -154,19 +153,20 @@ void ima_file_free(struct file *file) ima_check_last_writer(iint, inode, file); } -static int process_measurement(struct file *file, const char *filename, - int mask, int function) +static int process_measurement(struct file *file, int mask, int function, + int opened) { struct inode *inode = file_inode(file); - struct integrity_iint_cache *iint; + struct integrity_iint_cache *iint = NULL; struct ima_template_desc *template_desc; char *pathbuf = NULL; const char *pathname = NULL; - int rc = -ENOMEM, action, must_appraise, _func; + int rc = -ENOMEM, action, must_appraise; struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL; int xattr_len = 0; + bool violation_check; - if (!ima_initialized || !S_ISREG(inode->i_mode)) + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) return 0; /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action @@ -174,19 +174,33 @@ static int process_measurement(struct file *file, const char *filename, * Included is the appraise submask. */ action = ima_get_action(inode, mask, function); - if (!action) + violation_check = ((function == FILE_CHECK || function == MMAP_CHECK) && + (ima_policy_flag & IMA_MEASURE)); + if (!action && !violation_check) return 0; must_appraise = action & IMA_APPRAISE; /* Is the appraise rule hook specific? */ - _func = (action & IMA_FILE_APPRAISE) ? FILE_CHECK : function; + if (action & IMA_FILE_APPRAISE) + function = FILE_CHECK; mutex_lock(&inode->i_mutex); - iint = integrity_inode_get(inode); - if (!iint) - goto out; + if (action) { + iint = integrity_inode_get(inode); + if (!iint) + goto out; + } + + if (violation_check) { + ima_rdwr_violation_check(file, iint, action & IMA_MEASURE, + &pathbuf, &pathname); + if (!action) { + rc = 0; + goto out_free; + } + } /* Determine if already appraised/measured based on bitmask * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED, @@ -199,15 +213,13 @@ static int process_measurement(struct file *file, const char *filename, /* Nothing to do, just return existing appraised status */ if (!action) { if (must_appraise) - rc = ima_get_cache_status(iint, _func); + rc = ima_get_cache_status(iint, function); goto out_digsig; } template_desc = ima_template_desc_current(); - if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) { - if (action & IMA_APPRAISE_SUBMASK) - xattr_ptr = &xattr_value; - } else + if ((action & IMA_APPRAISE_SUBMASK) || + strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) xattr_ptr = &xattr_value; rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len); @@ -217,23 +229,26 @@ static int process_measurement(struct file *file, const char *filename, goto out_digsig; } - pathname = filename ?: ima_d_path(&file->f_path, &pathbuf); + if (!pathname) /* ima_rdwr_violation possibly pre-fetched */ + pathname = ima_d_path(&file->f_path, &pathbuf); if (action & IMA_MEASURE) ima_store_measurement(iint, file, pathname, xattr_value, xattr_len); if (action & IMA_APPRAISE_SUBMASK) - rc = ima_appraise_measurement(_func, iint, file, pathname, - xattr_value, xattr_len); + rc = ima_appraise_measurement(function, iint, file, pathname, + xattr_value, xattr_len, opened); if (action & IMA_AUDIT) ima_audit_measurement(iint, pathname); - kfree(pathbuf); + out_digsig: if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG)) rc = -EACCES; + kfree(xattr_value); +out_free: + kfree(pathbuf); out: mutex_unlock(&inode->i_mutex); - kfree(xattr_value); if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE)) return -EACCES; return 0; @@ -253,7 +268,7 @@ out: int ima_file_mmap(struct file *file, unsigned long prot) { if (file && (prot & PROT_EXEC)) - return process_measurement(file, NULL, MAY_EXEC, MMAP_CHECK); + return process_measurement(file, MAY_EXEC, MMAP_CHECK, 0); return 0; } @@ -272,10 +287,7 @@ int ima_file_mmap(struct file *file, unsigned long prot) */ int ima_bprm_check(struct linux_binprm *bprm) { - return process_measurement(bprm->file, - (strcmp(bprm->filename, bprm->interp) == 0) ? - bprm->filename : bprm->interp, - MAY_EXEC, BPRM_CHECK); + return process_measurement(bprm->file, MAY_EXEC, BPRM_CHECK, 0); } /** @@ -288,12 +300,11 @@ int ima_bprm_check(struct linux_binprm *bprm) * On success return 0. On integrity appraisal error, assuming the file * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. */ -int ima_file_check(struct file *file, int mask) +int ima_file_check(struct file *file, int mask, int opened) { - ima_rdwr_violation_check(file); - return process_measurement(file, NULL, + return process_measurement(file, mask & (MAY_READ | MAY_WRITE | MAY_EXEC), - FILE_CHECK); + FILE_CHECK, opened); } EXPORT_SYMBOL_GPL(ima_file_check); @@ -316,7 +327,7 @@ int ima_module_check(struct file *file) #endif return 0; /* We rely on module signature checking */ } - return process_measurement(file, NULL, MAY_EXEC, MODULE_CHECK); + return process_measurement(file, MAY_EXEC, MODULE_CHECK, 0); } int ima_fw_from_file(struct file *file, char *buf, size_t size) @@ -327,7 +338,7 @@ int ima_fw_from_file(struct file *file, char *buf, size_t size) return -EACCES; /* INTEGRITY_UNKNOWN */ return 0; } - return process_measurement(file, NULL, MAY_EXEC, FIRMWARE_CHECK); + return process_measurement(file, MAY_EXEC, FIRMWARE_CHECK, 0); } static int __init init_ima(void) @@ -336,14 +347,10 @@ static int __init init_ima(void) hash_setup(CONFIG_IMA_DEFAULT_HASH); error = ima_init(); - if (error) - goto out; - - error = ima_init_keyring(INTEGRITY_KEYRING_IMA); - if (error) - goto out; - ima_initialized = 1; -out: + if (!error) { + ima_initialized = 1; + ima_update_policy_flag(); + } return error; } |