diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 74c6702de74e..62e7cd687e9c 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -29,6 +29,7 @@ Description: base: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK] [FIRMWARE_CHECK] [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] + [KEXEC_CMDLINE] mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND] [[^]MAY_EXEC] fsmagic:= hex value diff --git a/include/linux/ima.h b/include/linux/ima.h index edd6d9195ce1..32b52835ffd5 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -26,6 +26,7 @@ extern int ima_read_file(struct file *file, enum kernel_read_file_id id); extern int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id); extern void ima_post_path_mknod(struct dentry *dentry); +extern void ima_kexec_cmdline(const void *buf, int size); #ifdef CONFIG_IMA_KEXEC extern void ima_add_kexec_buffer(struct kimage *image); @@ -74,6 +75,7 @@ static inline void ima_post_path_mknod(struct dentry *dentry) return; } +static inline void ima_kexec_cmdline(const void *buf, int size) {} #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e2916b115b93..936e0df4ae18 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -185,6 +185,7 @@ static inline unsigned int ima_hash_key(u8 *digest) hook(KEXEC_KERNEL_CHECK) \ hook(KEXEC_INITRAMFS_CHECK) \ hook(POLICY_CHECK) \ + hook(KEXEC_CMDLINE) \ hook(MAX_CHECK) #define __ima_hook_enumify(ENUM) ENUM, diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 682fe18c7a16..ca8cbc156f8f 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -168,6 +168,7 @@ err_out: * subj=, obj=, type=, func=, mask=, fsmagic= * subj,obj, and type: are LSM specific. * func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK + * | KEXEC_CMDLINE * mask: contains the permission mask * fsmagic: hex value * diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index d9a33d433b9f..12890eaaa51d 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -553,6 +553,78 @@ int ima_load_data(enum kernel_load_data_id id) return 0; } +/* + * process_buffer_measurement - Measure the buffer to ima log. + * @buf: pointer to the buffer that needs to be added to the log. + * @size: size of buffer(in bytes). + * @eventname: event name to be used for the buffer entry. + * @cred: a pointer to a credentials structure for user validation. + * @secid: the secid of the task to be validated. + * + * Based on policy, the buffer is measured into the ima log. + */ +static void process_buffer_measurement(const void *buf, int size, + const char *eventname, + const struct cred *cred, u32 secid) +{ + int ret = 0; + struct ima_template_entry *entry = NULL; + struct integrity_iint_cache iint = {}; + struct ima_event_data event_data = {.iint = &iint, + .filename = eventname}; + struct ima_template_desc *template_desc = NULL; + struct { + struct ima_digest_data hdr; + char digest[IMA_MAX_DIGEST_SIZE]; + } hash = {}; + int violation = 0; + int pcr = CONFIG_IMA_MEASURE_PCR_IDX; + int action = 0; + + action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr, + &template_desc); + if (!(action & IMA_MEASURE)) + return; + + iint.ima_hash = &hash.hdr; + iint.ima_hash->algo = ima_hash_algo; + iint.ima_hash->length = hash_digest_size[ima_hash_algo]; + + ret = ima_calc_buffer_hash(buf, size, iint.ima_hash); + if (ret < 0) + goto out; + + ret = ima_alloc_init_template(&event_data, &entry, template_desc); + if (ret < 0) + goto out; + + ret = ima_store_template(entry, violation, NULL, buf, pcr); + + if (ret < 0) + ima_free_template_entry(entry); + +out: + return; +} + +/** + * ima_kexec_cmdline - measure kexec cmdline boot args + * @buf: pointer to buffer + * @size: size of buffer + * + * Buffers can only be measured, not appraised. + */ +void ima_kexec_cmdline(const void *buf, int size) +{ + u32 secid; + + if (buf && size != 0) { + security_task_getsecid(current, &secid); + process_buffer_measurement(buf, size, "kexec-cmdline", + current_cred(), secid); + } +} + static int __init init_ima(void) { int error; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 7ae335a51b96..66851fd6f62d 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -298,6 +298,11 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, { int i; + if (func == KEXEC_CMDLINE) { + if ((rule->flags & IMA_FUNC) && (rule->func == func)) + return true; + return false; + } if ((rule->flags & IMA_FUNC) && (rule->func != func && func != POST_SETATTR)) return false; @@ -801,6 +806,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->func = KEXEC_INITRAMFS_CHECK; else if (strcmp(args[0].from, "POLICY_CHECK") == 0) entry->func = POLICY_CHECK; + else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0) + entry->func = KEXEC_CMDLINE; else result = -EINVAL; if (!result)