diff options
Diffstat (limited to 'kernel/security/smack/smackfs.c')
| -rw-r--r-- | kernel/security/smack/smackfs.c | 893 |
1 files changed, 685 insertions, 208 deletions
diff --git a/kernel/security/smack/smackfs.c b/kernel/security/smack/smackfs.c index ac4cac7c6..94bd9e41c 100644 --- a/kernel/security/smack/smackfs.c +++ b/kernel/security/smack/smackfs.c @@ -29,6 +29,7 @@ #include <linux/magic.h> #include "smack.h" +#define BEBITS (sizeof(__be32) * 8) /* * smackfs pseudo filesystem. */ @@ -40,7 +41,7 @@ enum smk_inos { SMK_DOI = 5, /* CIPSO DOI */ SMK_DIRECT = 6, /* CIPSO level indicating direct label */ SMK_AMBIENT = 7, /* internet ambient label */ - SMK_NETLBLADDR = 8, /* single label hosts */ + SMK_NET4ADDR = 8, /* single label hosts */ SMK_ONLYCAP = 9, /* the only "capable" label */ SMK_LOGGING = 10, /* logging */ SMK_LOAD_SELF = 11, /* task specific rules */ @@ -57,6 +58,10 @@ enum smk_inos { #ifdef CONFIG_SECURITY_SMACK_BRINGUP SMK_UNCONFINED = 22, /* define an unconfined label */ #endif +#if IS_ENABLED(CONFIG_IPV6) + SMK_NET6ADDR = 23, /* single label IPv6 hosts */ +#endif /* CONFIG_IPV6 */ + SMK_RELABEL_SELF = 24, /* relabel possible without CAP_MAC_ADMIN */ }; /* @@ -64,7 +69,10 @@ enum smk_inos { */ static DEFINE_MUTEX(smack_cipso_lock); static DEFINE_MUTEX(smack_ambient_lock); -static DEFINE_MUTEX(smk_netlbladdr_lock); +static DEFINE_MUTEX(smk_net4addr_lock); +#if IS_ENABLED(CONFIG_IPV6) +static DEFINE_MUTEX(smk_net6addr_lock); +#endif /* CONFIG_IPV6 */ /* * This is the "ambient" label for network traffic. @@ -87,16 +95,6 @@ int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT; */ int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT; -/* - * Unless a process is running with this label even - * having CAP_MAC_OVERRIDE isn't enough to grant - * privilege to violate MAC policy. If no label is - * designated (the NULL case) capabilities apply to - * everyone. It is expected that the hat (^) label - * will be used if any label is used. - */ -struct smack_known *smack_onlycap; - #ifdef CONFIG_SECURITY_SMACK_BRINGUP /* * Allow one label to be unconfined. This is for @@ -128,7 +126,10 @@ int smack_ptrace_rule = SMACK_PTRACE_DEFAULT; * can write to the specified label. */ -LIST_HEAD(smk_netlbladdr_list); +LIST_HEAD(smk_net4addr_list); +#if IS_ENABLED(CONFIG_IPV6) +LIST_HEAD(smk_net6addr_list); +#endif /* CONFIG_IPV6 */ /* * Rule lists are maintained for each label. @@ -139,7 +140,7 @@ struct smack_master_list { struct smack_rule *smk_rule; }; -LIST_HEAD(smack_rule_list); +static LIST_HEAD(smack_rule_list); struct smack_parsed_rule { struct smack_known *smk_subject; @@ -150,11 +151,6 @@ struct smack_parsed_rule { static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT; -struct smack_known smack_cipso_option = { - .smk_known = SMACK_CIPSO_OPTION, - .smk_secid = 0, -}; - /* * Values for parsing cipso rules * SMK_DIGITLEN: Length of a digit field in a rule. @@ -338,8 +334,7 @@ static int smk_perm_from_str(const char *string) * @import: if non-zero, import labels * @len: label length limit * - * Returns 0 on success, -EINVAL on failure and -ENOENT when either subject - * or object is missing. + * Returns 0 on success, appropriate error code on failure. */ static int smk_fill_rule(const char *subject, const char *object, const char *access1, const char *access2, @@ -351,16 +346,16 @@ static int smk_fill_rule(const char *subject, const char *object, if (import) { rule->smk_subject = smk_import_entry(subject, len); - if (rule->smk_subject == NULL) - return -EINVAL; + if (IS_ERR(rule->smk_subject)) + return PTR_ERR(rule->smk_subject); rule->smk_object = smk_import_entry(object, len); - if (rule->smk_object == NULL) - return -EINVAL; + if (IS_ERR(rule->smk_object)) + return PTR_ERR(rule->smk_object); } else { cp = smk_parse_smack(subject, len); - if (cp == NULL) - return -EINVAL; + if (IS_ERR(cp)) + return PTR_ERR(cp); skp = smk_find_entry(cp); kfree(cp); if (skp == NULL) @@ -368,8 +363,8 @@ static int smk_fill_rule(const char *subject, const char *object, rule->smk_subject = skp; cp = smk_parse_smack(object, len); - if (cp == NULL) - return -EINVAL; + if (IS_ERR(cp)) + return PTR_ERR(cp); skp = smk_find_entry(cp); kfree(cp); if (skp == NULL) @@ -412,7 +407,7 @@ static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule, * @import: if non-zero, import labels * @tokens: numer of substrings expected in data * - * Returns number of processed bytes on success, -1 on failure. + * Returns number of processed bytes on success, -ERRNO on failure. */ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, int import, int tokens) @@ -431,7 +426,7 @@ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, if (data[cnt] == '\0') /* Unexpected end of data */ - return -1; + return -EINVAL; tok[i] = data + cnt; @@ -529,14 +524,14 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, while (cnt < count) { if (format == SMK_FIXED24_FMT) { rc = smk_parse_rule(data, &rule, 1); - if (rc != 0) { - rc = -EINVAL; + if (rc < 0) goto out; - } cnt = count; } else { rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens); - if (rc <= 0) { + if (rc < 0) + goto out; + if (rc == 0) { rc = -EINVAL; goto out; } @@ -567,23 +562,17 @@ static void *smk_seq_start(struct seq_file *s, loff_t *pos, struct list_head *head) { struct list_head *list; + int i = *pos; + + rcu_read_lock(); + for (list = rcu_dereference(list_next_rcu(head)); + list != head; + list = rcu_dereference(list_next_rcu(list))) { + if (i-- == 0) + return list; + } - /* - * This is 0 the first time through. - */ - if (s->index == 0) - s->private = head; - - if (s->private == NULL) - return NULL; - - list = s->private; - if (list_empty(list)) - return NULL; - - if (s->index == 0) - return list->next; - return list; + return NULL; } static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, @@ -591,17 +580,15 @@ static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, { struct list_head *list = v; - if (list_is_last(list, head)) { - s->private = NULL; - return NULL; - } - s->private = list->next; - return list->next; + ++*pos; + list = rcu_dereference(list_next_rcu(list)); + + return (list == head) ? NULL : list; } static void smk_seq_stop(struct seq_file *s, void *v) { - /* No-op */ + rcu_read_unlock(); } static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max) @@ -661,7 +648,7 @@ static int load_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_master_list *smlp = - list_entry(list, struct smack_master_list, list); + list_entry_rcu(list, struct smack_master_list, list); smk_rule_show(s, smlp->smk_rule, SMK_LABELLEN); @@ -809,7 +796,7 @@ static int cipso_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_known *skp = - list_entry(list, struct smack_known, list); + list_entry_rcu(list, struct smack_known, list); struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; char sep = '/'; int i; @@ -915,8 +902,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, mutex_lock(&smack_cipso_lock); skp = smk_import_entry(rule, 0); - if (skp == NULL) + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); goto out; + } if (format == SMK_FIXED24_FMT) rule += SMK_LABELLEN; @@ -998,7 +987,7 @@ static int cipso2_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_known *skp = - list_entry(list, struct smack_known, list); + list_entry_rcu(list, struct smack_known, list); struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; char sep = '/'; int i; @@ -1064,92 +1053,90 @@ static const struct file_operations smk_cipso2_ops = { * Seq_file read operations for /smack/netlabel */ -static void *netlbladdr_seq_start(struct seq_file *s, loff_t *pos) +static void *net4addr_seq_start(struct seq_file *s, loff_t *pos) { - return smk_seq_start(s, pos, &smk_netlbladdr_list); + return smk_seq_start(s, pos, &smk_net4addr_list); } -static void *netlbladdr_seq_next(struct seq_file *s, void *v, loff_t *pos) +static void *net4addr_seq_next(struct seq_file *s, void *v, loff_t *pos) { - return smk_seq_next(s, v, pos, &smk_netlbladdr_list); + return smk_seq_next(s, v, pos, &smk_net4addr_list); } -#define BEBITS (sizeof(__be32) * 8) /* * Print host/label pairs */ -static int netlbladdr_seq_show(struct seq_file *s, void *v) +static int net4addr_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; - struct smk_netlbladdr *skp = - list_entry(list, struct smk_netlbladdr, list); - unsigned char *hp = (char *) &skp->smk_host.sin_addr.s_addr; - int maskn; - u32 temp_mask = be32_to_cpu(skp->smk_mask.s_addr); + struct smk_net4addr *skp = + list_entry_rcu(list, struct smk_net4addr, list); + char *kp = SMACK_CIPSO_OPTION; - for (maskn = 0; temp_mask; temp_mask <<= 1, maskn++); - - seq_printf(s, "%u.%u.%u.%u/%d %s\n", - hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label->smk_known); + if (skp->smk_label != NULL) + kp = skp->smk_label->smk_known; + seq_printf(s, "%pI4/%d %s\n", &skp->smk_host.s_addr, + skp->smk_masks, kp); return 0; } -static const struct seq_operations netlbladdr_seq_ops = { - .start = netlbladdr_seq_start, - .next = netlbladdr_seq_next, - .show = netlbladdr_seq_show, +static const struct seq_operations net4addr_seq_ops = { + .start = net4addr_seq_start, + .next = net4addr_seq_next, + .show = net4addr_seq_show, .stop = smk_seq_stop, }; /** - * smk_open_netlbladdr - open() for /smack/netlabel + * smk_open_net4addr - open() for /smack/netlabel * @inode: inode structure representing file * @file: "netlabel" file pointer * - * Connect our netlbladdr_seq_* operations with /smack/netlabel + * Connect our net4addr_seq_* operations with /smack/netlabel * file_operations */ -static int smk_open_netlbladdr(struct inode *inode, struct file *file) +static int smk_open_net4addr(struct inode *inode, struct file *file) { - return seq_open(file, &netlbladdr_seq_ops); + return seq_open(file, &net4addr_seq_ops); } /** - * smk_netlbladdr_insert + * smk_net4addr_insert * @new : netlabel to insert * - * This helper insert netlabel in the smack_netlbladdrs list + * This helper insert netlabel in the smack_net4addrs list * sorted by netmask length (longest to smallest) - * locked by &smk_netlbladdr_lock in smk_write_netlbladdr + * locked by &smk_net4addr_lock in smk_write_net4addr * */ -static void smk_netlbladdr_insert(struct smk_netlbladdr *new) +static void smk_net4addr_insert(struct smk_net4addr *new) { - struct smk_netlbladdr *m, *m_next; + struct smk_net4addr *m; + struct smk_net4addr *m_next; - if (list_empty(&smk_netlbladdr_list)) { - list_add_rcu(&new->list, &smk_netlbladdr_list); + if (list_empty(&smk_net4addr_list)) { + list_add_rcu(&new->list, &smk_net4addr_list); return; } - m = list_entry_rcu(smk_netlbladdr_list.next, - struct smk_netlbladdr, list); + m = list_entry_rcu(smk_net4addr_list.next, + struct smk_net4addr, list); /* the comparison '>' is a bit hacky, but works */ - if (new->smk_mask.s_addr > m->smk_mask.s_addr) { - list_add_rcu(&new->list, &smk_netlbladdr_list); + if (new->smk_masks > m->smk_masks) { + list_add_rcu(&new->list, &smk_net4addr_list); return; } - list_for_each_entry_rcu(m, &smk_netlbladdr_list, list) { - if (list_is_last(&m->list, &smk_netlbladdr_list)) { + list_for_each_entry_rcu(m, &smk_net4addr_list, list) { + if (list_is_last(&m->list, &smk_net4addr_list)) { list_add_rcu(&new->list, &m->list); return; } m_next = list_entry_rcu(m->list.next, - struct smk_netlbladdr, list); - if (new->smk_mask.s_addr > m_next->smk_mask.s_addr) { + struct smk_net4addr, list); + if (new->smk_masks > m_next->smk_masks) { list_add_rcu(&new->list, &m->list); return; } @@ -1158,28 +1145,29 @@ static void smk_netlbladdr_insert(struct smk_netlbladdr *new) /** - * smk_write_netlbladdr - write() for /smack/netlabel + * smk_write_net4addr - write() for /smack/netlabel * @file: file pointer, not actually used * @buf: where to get the data from * @count: bytes sent * @ppos: where to start * - * Accepts only one netlbladdr per write call. + * Accepts only one net4addr per write call. * Returns number of bytes written or error code, as appropriate */ -static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, +static ssize_t smk_write_net4addr(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - struct smk_netlbladdr *snp; + struct smk_net4addr *snp; struct sockaddr_in newname; char *smack; - struct smack_known *skp; + struct smack_known *skp = NULL; char *data; char *host = (char *)&newname.sin_addr.s_addr; int rc; struct netlbl_audit audit_info; struct in_addr mask; unsigned int m; + unsigned int masks; int found; u32 mask_bits = (1<<31); __be32 nsa; @@ -1217,7 +1205,7 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, data[count] = '\0'; rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s", - &host[0], &host[1], &host[2], &host[3], &m, smack); + &host[0], &host[1], &host[2], &host[3], &masks, smack); if (rc != 6) { rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s", &host[0], &host[1], &host[2], &host[3], smack); @@ -1226,8 +1214,9 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, goto free_out; } m = BEBITS; + masks = 32; } - if (m > BEBITS) { + if (masks > BEBITS) { rc = -EINVAL; goto free_out; } @@ -1237,21 +1226,21 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, */ if (smack[0] != '-') { skp = smk_import_entry(smack, 0); - if (skp == NULL) { - rc = -EINVAL; + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); goto free_out; } } else { - /* check known options */ - if (strcmp(smack, smack_cipso_option.smk_known) == 0) - skp = &smack_cipso_option; - else { + /* + * Only the -CIPSO option is supported for IPv4 + */ + if (strcmp(smack, SMACK_CIPSO_OPTION) != 0) { rc = -EINVAL; goto free_out; } } - for (temp_mask = 0; m > 0; m--) { + for (m = masks, temp_mask = 0; m > 0; m--) { temp_mask |= mask_bits; mask_bits >>= 1; } @@ -1262,14 +1251,13 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, * Only allow one writer at a time. Writes should be * quite rare and small in any case. */ - mutex_lock(&smk_netlbladdr_lock); + mutex_lock(&smk_net4addr_lock); nsa = newname.sin_addr.s_addr; /* try to find if the prefix is already in the list */ found = 0; - list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) { - if (snp->smk_host.sin_addr.s_addr == nsa && - snp->smk_mask.s_addr == mask.s_addr) { + list_for_each_entry_rcu(snp, &smk_net4addr_list, list) { + if (snp->smk_host.s_addr == nsa && snp->smk_masks == masks) { found = 1; break; } @@ -1282,17 +1270,20 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, rc = -ENOMEM; else { rc = 0; - snp->smk_host.sin_addr.s_addr = newname.sin_addr.s_addr; + snp->smk_host.s_addr = newname.sin_addr.s_addr; snp->smk_mask.s_addr = mask.s_addr; snp->smk_label = skp; - smk_netlbladdr_insert(snp); + snp->smk_masks = masks; + smk_net4addr_insert(snp); } } else { - /* we delete the unlabeled entry, only if the previous label - * wasn't the special CIPSO option */ - if (snp->smk_label != &smack_cipso_option) + /* + * Delete the unlabeled entry, only if the previous label + * wasn't the special CIPSO option + */ + if (snp->smk_label != NULL) rc = netlbl_cfg_unlbl_static_del(&init_net, NULL, - &snp->smk_host.sin_addr, &snp->smk_mask, + &snp->smk_host, &snp->smk_mask, PF_INET, &audit_info); else rc = 0; @@ -1304,15 +1295,15 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, * this host so that incoming packets get labeled. * but only if we didn't get the special CIPSO option */ - if (rc == 0 && skp != &smack_cipso_option) + if (rc == 0 && skp != NULL) rc = netlbl_cfg_unlbl_static_add(&init_net, NULL, - &snp->smk_host.sin_addr, &snp->smk_mask, PF_INET, + &snp->smk_host, &snp->smk_mask, PF_INET, snp->smk_label->smk_secid, &audit_info); if (rc == 0) rc = count; - mutex_unlock(&smk_netlbladdr_lock); + mutex_unlock(&smk_net4addr_lock); free_out: kfree(smack); @@ -1322,14 +1313,279 @@ free_data_out: return rc; } -static const struct file_operations smk_netlbladdr_ops = { - .open = smk_open_netlbladdr, +static const struct file_operations smk_net4addr_ops = { + .open = smk_open_net4addr, .read = seq_read, .llseek = seq_lseek, - .write = smk_write_netlbladdr, + .write = smk_write_net4addr, .release = seq_release, }; +#if IS_ENABLED(CONFIG_IPV6) +/* + * Seq_file read operations for /smack/netlabel6 + */ + +static void *net6addr_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smk_net6addr_list); +} + +static void *net6addr_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smk_net6addr_list); +} + +/* + * Print host/label pairs + */ +static int net6addr_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smk_net6addr *skp = + list_entry(list, struct smk_net6addr, list); + + if (skp->smk_label != NULL) + seq_printf(s, "%pI6/%d %s\n", &skp->smk_host, skp->smk_masks, + skp->smk_label->smk_known); + + return 0; +} + +static const struct seq_operations net6addr_seq_ops = { + .start = net6addr_seq_start, + .next = net6addr_seq_next, + .show = net6addr_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_net6addr - open() for /smack/netlabel + * @inode: inode structure representing file + * @file: "netlabel" file pointer + * + * Connect our net6addr_seq_* operations with /smack/netlabel + * file_operations + */ +static int smk_open_net6addr(struct inode *inode, struct file *file) +{ + return seq_open(file, &net6addr_seq_ops); +} + +/** + * smk_net6addr_insert + * @new : entry to insert + * + * This inserts an entry in the smack_net6addrs list + * sorted by netmask length (longest to smallest) + * locked by &smk_net6addr_lock in smk_write_net6addr + * + */ +static void smk_net6addr_insert(struct smk_net6addr *new) +{ + struct smk_net6addr *m_next; + struct smk_net6addr *m; + + if (list_empty(&smk_net6addr_list)) { + list_add_rcu(&new->list, &smk_net6addr_list); + return; + } + + m = list_entry_rcu(smk_net6addr_list.next, + struct smk_net6addr, list); + + if (new->smk_masks > m->smk_masks) { + list_add_rcu(&new->list, &smk_net6addr_list); + return; + } + + list_for_each_entry_rcu(m, &smk_net6addr_list, list) { + if (list_is_last(&m->list, &smk_net6addr_list)) { + list_add_rcu(&new->list, &m->list); + return; + } + m_next = list_entry_rcu(m->list.next, + struct smk_net6addr, list); + if (new->smk_masks > m_next->smk_masks) { + list_add_rcu(&new->list, &m->list); + return; + } + } +} + + +/** + * smk_write_net6addr - write() for /smack/netlabel + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one net6addr per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_net6addr(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smk_net6addr *snp; + struct in6_addr newname; + struct in6_addr fullmask; + struct smack_known *skp = NULL; + char *smack; + char *data; + int rc = 0; + int found = 0; + int i; + unsigned int scanned[8]; + unsigned int m; + unsigned int mask = 128; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + * "<addr/mask, as a:b:c:d:e:f:g:h/e><space><label>" + * "<addr, as a:b:c:d:e:f:g:h><space><label>" + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count < SMK_NETLBLADDRMIN) + return -EINVAL; + + data = kzalloc(count + 1, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto free_data_out; + } + + smack = kzalloc(count + 1, GFP_KERNEL); + if (smack == NULL) { + rc = -ENOMEM; + goto free_data_out; + } + + data[count] = '\0'; + + i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s", + &scanned[0], &scanned[1], &scanned[2], &scanned[3], + &scanned[4], &scanned[5], &scanned[6], &scanned[7], + &mask, smack); + if (i != 10) { + i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x %s", + &scanned[0], &scanned[1], &scanned[2], + &scanned[3], &scanned[4], &scanned[5], + &scanned[6], &scanned[7], smack); + if (i != 9) { + rc = -EINVAL; + goto free_out; + } + } + if (mask > 128) { + rc = -EINVAL; + goto free_out; + } + for (i = 0; i < 8; i++) { + if (scanned[i] > 0xffff) { + rc = -EINVAL; + goto free_out; + } + newname.s6_addr16[i] = htons(scanned[i]); + } + + /* + * If smack begins with '-', it is an option, don't import it + */ + if (smack[0] != '-') { + skp = smk_import_entry(smack, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto free_out; + } + } else { + /* + * Only -DELETE is supported for IPv6 + */ + if (strcmp(smack, SMACK_DELETE_OPTION) != 0) { + rc = -EINVAL; + goto free_out; + } + } + + for (i = 0, m = mask; i < 8; i++) { + if (m >= 16) { + fullmask.s6_addr16[i] = 0xffff; + m -= 16; + } else if (m > 0) { + fullmask.s6_addr16[i] = (1 << m) - 1; + m = 0; + } else + fullmask.s6_addr16[i] = 0; + newname.s6_addr16[i] &= fullmask.s6_addr16[i]; + } + + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smk_net6addr_lock); + /* + * Try to find the prefix in the list + */ + list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { + if (mask != snp->smk_masks) + continue; + for (found = 1, i = 0; i < 8; i++) { + if (newname.s6_addr16[i] != + snp->smk_host.s6_addr16[i]) { + found = 0; + break; + } + } + if (found == 1) + break; + } + if (found == 0) { + snp = kzalloc(sizeof(*snp), GFP_KERNEL); + if (snp == NULL) + rc = -ENOMEM; + else { + snp->smk_host = newname; + snp->smk_mask = fullmask; + snp->smk_masks = mask; + snp->smk_label = skp; + smk_net6addr_insert(snp); + } + } else { + snp->smk_label = skp; + } + + if (rc == 0) + rc = count; + + mutex_unlock(&smk_net6addr_lock); + +free_out: + kfree(smack); +free_data_out: + kfree(data); + + return rc; +} + +static const struct file_operations smk_net6addr_ops = { + .open = smk_open_net6addr, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_net6addr, + .release = seq_release, +}; +#endif /* CONFIG_IPV6 */ + /** * smk_read_doi - read() for /smack/doi * @filp: file pointer, not actually used @@ -1619,8 +1875,8 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf, } skp = smk_import_entry(data, count); - if (skp == NULL) { - rc = -EINVAL; + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); goto out; } @@ -1643,34 +1899,127 @@ static const struct file_operations smk_ambient_ops = { .llseek = default_llseek, }; +/* + * Seq_file operations for /smack/onlycap + */ +static void *onlycap_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_onlycap_list); +} + +static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_onlycap_list); +} + +static int onlycap_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known_list_elem *sklep = + list_entry_rcu(list, struct smack_known_list_elem, list); + + seq_puts(s, sklep->smk_label->smk_known); + seq_putc(s, ' '); + + return 0; +} + +static const struct seq_operations onlycap_seq_ops = { + .start = onlycap_seq_start, + .next = onlycap_seq_next, + .show = onlycap_seq_show, + .stop = smk_seq_stop, +}; + +static int smk_open_onlycap(struct inode *inode, struct file *file) +{ + return seq_open(file, &onlycap_seq_ops); +} + /** - * smk_read_onlycap - read() for smackfs/onlycap - * @filp: file pointer, not actually used - * @buf: where to put the result - * @cn: maximum to send along - * @ppos: where to start + * smk_list_swap_rcu - swap public list with a private one in RCU-safe way + * The caller must hold appropriate mutex to prevent concurrent modifications + * to the public list. + * Private list is assumed to be not accessible to other threads yet. * - * Returns number of bytes read or error code, as appropriate + * @public: public list + * @private: private list */ -static ssize_t smk_read_onlycap(struct file *filp, char __user *buf, - size_t cn, loff_t *ppos) +static void smk_list_swap_rcu(struct list_head *public, + struct list_head *private) { - char *smack = ""; - ssize_t rc = -EINVAL; - int asize; + struct list_head *first, *last; - if (*ppos != 0) - return 0; + if (list_empty(public)) { + list_splice_init_rcu(private, public, synchronize_rcu); + } else { + /* Remember public list before replacing it */ + first = public->next; + last = public->prev; + + /* Publish private list in place of public in RCU-safe way */ + private->prev->next = public; + private->next->prev = public; + rcu_assign_pointer(public->next, private->next); + public->prev = private->prev; + + synchronize_rcu(); + + /* When all readers are done with the old public list, + * attach it in place of private */ + private->next = first; + private->prev = last; + first->prev = private; + last->next = private; + } +} + +/** + * smk_parse_label_list - parse list of Smack labels, separated by spaces + * + * @data: the string to parse + * @private: destination list + * + * Returns zero on success or error code, as appropriate + */ +static int smk_parse_label_list(char *data, struct list_head *list) +{ + char *tok; + struct smack_known *skp; + struct smack_known_list_elem *sklep; - if (smack_onlycap != NULL) - smack = smack_onlycap->smk_known; + while ((tok = strsep(&data, " ")) != NULL) { + if (!*tok) + continue; - asize = strlen(smack) + 1; + skp = smk_import_entry(tok, 0); + if (IS_ERR(skp)) + return PTR_ERR(skp); - if (cn >= asize) - rc = simple_read_from_buffer(buf, cn, ppos, smack, asize); + sklep = kzalloc(sizeof(*sklep), GFP_KERNEL); + if (sklep == NULL) + return -ENOMEM; - return rc; + sklep->smk_label = skp; + list_add(&sklep->list, list); + } + + return 0; +} + +/** + * smk_destroy_label_list - destroy a list of smack_known_list_elem + * @head: header pointer of the list to destroy + */ +void smk_destroy_label_list(struct list_head *list) +{ + struct smack_known_list_elem *sklep; + struct smack_known_list_elem *sklep2; + + list_for_each_entry_safe(sklep, sklep2, list, list) + kfree(sklep); + + INIT_LIST_HEAD(list); } /** @@ -1686,47 +2035,52 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char *data; - struct smack_known *skp = smk_of_task(current->cred->security); - int rc = count; + LIST_HEAD(list_tmp); + int rc; if (!smack_privileged(CAP_MAC_ADMIN)) return -EPERM; - /* - * This can be done using smk_access() but is done - * explicitly for clarity. The smk_access() implementation - * would use smk_access(smack_onlycap, MAY_WRITE) - */ - if (smack_onlycap != NULL && smack_onlycap != skp) - return -EPERM; - data = kzalloc(count + 1, GFP_KERNEL); if (data == NULL) return -ENOMEM; + if (copy_from_user(data, buf, count) != 0) { + kfree(data); + return -EFAULT; + } + + rc = smk_parse_label_list(data, &list_tmp); + kfree(data); + /* - * Should the null string be passed in unset the onlycap value. - * This seems like something to be careful with as usually - * smk_import only expects to return NULL for errors. It - * is usually the case that a nullstring or "\n" would be - * bad to pass to smk_import but in fact this is useful here. + * Clear the smack_onlycap on invalid label errors. This means + * that we can pass a null string to unset the onlycap value. * - * smk_import will also reject a label beginning with '-', + * Importing will also reject a label beginning with '-', * so "-usecapabilities" will also work. + * + * But do so only on invalid label, not on system errors. + * The invalid label must be first to count as clearing attempt. */ - if (copy_from_user(data, buf, count) != 0) - rc = -EFAULT; - else - smack_onlycap = smk_import_entry(data, count); + if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) { + mutex_lock(&smack_onlycap_lock); + smk_list_swap_rcu(&smack_onlycap_list, &list_tmp); + mutex_unlock(&smack_onlycap_lock); + rc = count; + } + + smk_destroy_label_list(&list_tmp); - kfree(data); return rc; } static const struct file_operations smk_onlycap_ops = { - .read = smk_read_onlycap, + .open = smk_open_onlycap, + .read = seq_read, .write = smk_write_onlycap, - .llseek = default_llseek, + .llseek = seq_lseek, + .release = seq_release, }; #ifdef CONFIG_SECURITY_SMACK_BRINGUP @@ -1773,6 +2127,7 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char *data; + struct smack_known *skp; int rc = count; if (!smack_privileged(CAP_MAC_ADMIN)) @@ -1782,21 +2137,31 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf, if (data == NULL) return -ENOMEM; + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto freeout; + } + /* - * Should the null string be passed in unset the unconfined value. - * This seems like something to be careful with as usually - * smk_import only expects to return NULL for errors. It - * is usually the case that a nullstring or "\n" would be - * bad to pass to smk_import but in fact this is useful here. + * Clear the smack_unconfined on invalid label errors. This means + * that we can pass a null string to unset the unconfined value. * - * smk_import will also reject a label beginning with '-', + * Importing will also reject a label beginning with '-', * so "-confine" will also work. + * + * But do so only on invalid label, not on system errors. */ - if (copy_from_user(data, buf, count) != 0) - rc = -EFAULT; - else - smack_unconfined = smk_import_entry(data, count); + skp = smk_import_entry(data, count); + if (PTR_ERR(skp) == -EINVAL) + skp = NULL; + else if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto freeout; + } + + smack_unconfined = skp; +freeout: kfree(data); return rc; } @@ -1895,7 +2260,7 @@ static int load_self_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_rule *srp = - list_entry(list, struct smack_rule, list); + list_entry_rcu(list, struct smack_rule, list); smk_rule_show(s, srp, SMK_LABELLEN); @@ -1980,7 +2345,7 @@ static ssize_t smk_user_access(struct file *file, const char __user *buf, res = smk_access(rule.smk_subject, rule.smk_object, rule.smk_access1, NULL); else if (res != -ENOENT) - return -EINVAL; + return res; /* * smk_access() can return a value > 0 in the "bringup" case. @@ -2024,7 +2389,7 @@ static int load2_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_master_list *smlp = - list_entry(list, struct smack_master_list, list); + list_entry_rcu(list, struct smack_master_list, list); smk_rule_show(s, smlp->smk_rule, SMK_LONGLABEL); @@ -2101,7 +2466,7 @@ static int load_self2_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_rule *srp = - list_entry(list, struct smack_rule, list); + list_entry_rcu(list, struct smack_rule, list); smk_rule_show(s, srp, SMK_LONGLABEL); @@ -2182,8 +2547,8 @@ static const struct file_operations smk_access2_ops = { static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { - char *data = NULL; - const char *cp = NULL; + char *data; + const char *cp; struct smack_known *skp; struct smack_rule *sp; struct list_head *rule_list; @@ -2205,18 +2570,18 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, if (copy_from_user(data, buf, count) != 0) { rc = -EFAULT; - goto free_out; + goto out_data; } cp = smk_parse_smack(data, count); - if (cp == NULL) { - rc = -EINVAL; - goto free_out; + if (IS_ERR(cp)) { + rc = PTR_ERR(cp); + goto out_data; } skp = smk_find_entry(cp); if (skp == NULL) - goto free_out; + goto out_cp; rule_list = &skp->smk_rules; rule_lock = &skp->smk_rules_lock; @@ -2228,9 +2593,11 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, mutex_unlock(rule_lock); -free_out: - kfree(data); +out_cp: kfree(cp); +out_data: + kfree(data); + return rc; } @@ -2247,11 +2614,7 @@ static const struct file_operations smk_revoke_subj_ops = { */ static int smk_init_sysfs(void) { - int err; - err = sysfs_create_mount_point(fs_kobj, "smackfs"); - if (err) - return err; - return 0; + return sysfs_create_mount_point(fs_kobj, "smackfs"); } /** @@ -2341,10 +2704,10 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf, rc = -EFAULT; else { skp = smk_import_entry(data, count); - if (skp == NULL) - rc = -EINVAL; + if (IS_ERR(skp)) + rc = PTR_ERR(skp); else - smack_syslog_label = smk_import_entry(data, count); + smack_syslog_label = skp; } kfree(data); @@ -2357,6 +2720,113 @@ static const struct file_operations smk_syslog_ops = { .llseek = default_llseek, }; +/* + * Seq_file read operations for /smack/relabel-self + */ + +static void *relabel_self_seq_start(struct seq_file *s, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_start(s, pos, &tsp->smk_relabel); +} + +static void *relabel_self_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct task_smack *tsp = current_security(); + + return smk_seq_next(s, v, pos, &tsp->smk_relabel); +} + +static int relabel_self_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_known_list_elem *sklep = + list_entry(list, struct smack_known_list_elem, list); + + seq_puts(s, sklep->smk_label->smk_known); + seq_putc(s, ' '); + + return 0; +} + +static const struct seq_operations relabel_self_seq_ops = { + .start = relabel_self_seq_start, + .next = relabel_self_seq_next, + .show = relabel_self_seq_show, + .stop = smk_seq_stop, +}; + +/** + * smk_open_relabel_self - open() for /smack/relabel-self + * @inode: inode structure representing file + * @file: "relabel-self" file pointer + * + * Connect our relabel_self_seq_* operations with /smack/relabel-self + * file_operations + */ +static int smk_open_relabel_self(struct inode *inode, struct file *file) +{ + return seq_open(file, &relabel_self_seq_ops); +} + +/** + * smk_write_relabel_self - write() for /smack/relabel-self + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + */ +static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct task_smack *tsp = current_security(); + char *data; + int rc; + LIST_HEAD(list_tmp); + + /* + * Must have privilege. + */ + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + /* + * Enough data must be present. + */ + if (*ppos != 0) + return -EINVAL; + + data = kzalloc(count + 1, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + kfree(data); + return -EFAULT; + } + + rc = smk_parse_label_list(data, &list_tmp); + kfree(data); + + if (!rc || (rc == -EINVAL && list_empty(&list_tmp))) { + smk_destroy_label_list(&tsp->smk_relabel); + list_splice(&list_tmp, &tsp->smk_relabel); + return count; + } + + smk_destroy_label_list(&list_tmp); + return rc; +} + +static const struct file_operations smk_relabel_self_ops = { + .open = smk_open_relabel_self, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_relabel_self, + .release = seq_release, +}; /** * smk_read_ptrace - read() for /smack/ptrace @@ -2446,8 +2916,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) "direct", &smk_direct_ops, S_IRUGO|S_IWUSR}, [SMK_AMBIENT] = { "ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR}, - [SMK_NETLBLADDR] = { - "netlabel", &smk_netlbladdr_ops, S_IRUGO|S_IWUSR}, + [SMK_NET4ADDR] = { + "netlabel", &smk_net4addr_ops, S_IRUGO|S_IWUSR}, [SMK_ONLYCAP] = { "onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR}, [SMK_LOGGING] = { @@ -2479,6 +2949,13 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) [SMK_UNCONFINED] = { "unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR}, #endif +#if IS_ENABLED(CONFIG_IPV6) + [SMK_NET6ADDR] = { + "ipv6host", &smk_net6addr_ops, S_IRUGO|S_IWUSR}, +#endif /* CONFIG_IPV6 */ + [SMK_RELABEL_SELF] = { + "relabel-self", &smk_relabel_self_ops, + S_IRUGO|S_IWUGO}, /* last one */ {""} }; @@ -2547,7 +3024,7 @@ static int __init init_smk_fs(void) int err; int rc; - if (!security_module_enable(&smack_ops)) + if (smack_enabled == 0) return 0; err = smk_init_sysfs(); |