diff options
Diffstat (limited to 'security/smack/smackfs.c')
| -rw-r--r-- | security/smack/smackfs.c | 441 |
1 files changed, 298 insertions, 143 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 53a08b85bda..32b24882084 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -52,6 +52,8 @@ enum smk_inos { SMK_CIPSO2 = 17, /* load long label -> CIPSO mapping */ SMK_REVOKE_SUBJ = 18, /* set rules with subject label to '-' */ SMK_CHANGE_RULE = 19, /* change or add rules (long labels) */ + SMK_SYSLOG = 20, /* change syslog label) */ + SMK_PTRACE = 21, /* set ptrace rule */ }; /* @@ -59,6 +61,7 @@ enum smk_inos { */ static DEFINE_MUTEX(smack_cipso_lock); static DEFINE_MUTEX(smack_ambient_lock); +static DEFINE_MUTEX(smack_syslog_lock); static DEFINE_MUTEX(smk_netlbladdr_lock); /* @@ -66,7 +69,7 @@ static DEFINE_MUTEX(smk_netlbladdr_lock); * If it isn't somehow marked, use this. * It can be reset via smackfs/ambient */ -char *smack_net_ambient; +struct smack_known *smack_net_ambient; /* * This is the level in a CIPSO header that indicates a @@ -90,7 +93,22 @@ int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT; * everyone. It is expected that the hat (^) label * will be used if any label is used. */ -char *smack_onlycap; +struct smack_known *smack_onlycap; + +/* + * If this value is set restrict syslog use to the label specified. + * It can be reset via smackfs/syslog + */ +struct smack_known *smack_syslog_label; + +/* + * Ptrace current rule + * SMACK_PTRACE_DEFAULT regular smack ptrace rules (/proc based) + * SMACK_PTRACE_EXACT labels must match, but can be overriden with + * CAP_SYS_PTRACE + * SMACK_PTRACE_DRACONIAN lables must match, CAP_SYS_PTRACE has no effect + */ +int smack_ptrace_rule = SMACK_PTRACE_DEFAULT; /* * Certain IP addresses may be designated as single label hosts. @@ -112,7 +130,7 @@ struct smack_master_list { LIST_HEAD(smack_rule_list); struct smack_parsed_rule { - char *smk_subject; + struct smack_known *smk_subject; char *smk_object; int smk_access1; int smk_access2; @@ -139,7 +157,7 @@ const char *smack_cipso_option = SMACK_CIPSO_OPTION; * SMK_LOADLEN: Smack rule length */ #define SMK_OACCESS "rwxa" -#define SMK_ACCESS "rwxat" +#define SMK_ACCESS "rwxatl" #define SMK_OACCESSLEN (sizeof(SMK_OACCESS) - 1) #define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1) #define SMK_OLOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_OACCESSLEN) @@ -163,9 +181,11 @@ static inline void smack_catset_bit(unsigned int cat, char *catsetp) */ static void smk_netlabel_audit_set(struct netlbl_audit *nap) { + struct smack_known *skp = smk_of_current(); + nap->loginuid = audit_get_loginuid(current); nap->sessionid = audit_get_sessionid(current); - nap->secid = smack_to_secid(smk_of_current()); + nap->secid = skp->smk_secid; } /* @@ -280,6 +300,10 @@ static int smk_perm_from_str(const char *string) case 'T': perm |= MAY_TRANSMUTE; break; + case 'l': + case 'L': + perm |= MAY_LOCK; + break; default: return perm; } @@ -295,7 +319,8 @@ static int smk_perm_from_str(const char *string) * @import: if non-zero, import labels * @len: label length limit * - * Returns 0 on success, -1 on failure + * Returns 0 on success, -EINVAL on failure and -ENOENT when either subject + * or object is missing. */ static int smk_fill_rule(const char *subject, const char *object, const char *access1, const char *access2, @@ -306,30 +331,30 @@ static int smk_fill_rule(const char *subject, const char *object, struct smack_known *skp; if (import) { - rule->smk_subject = smk_import(subject, len); + rule->smk_subject = smk_import_entry(subject, len); if (rule->smk_subject == NULL) - return -1; + return -EINVAL; rule->smk_object = smk_import(object, len); if (rule->smk_object == NULL) - return -1; + return -EINVAL; } else { cp = smk_parse_smack(subject, len); if (cp == NULL) - return -1; + return -EINVAL; skp = smk_find_entry(cp); kfree(cp); if (skp == NULL) - return -1; - rule->smk_subject = skp->smk_known; + return -ENOENT; + rule->smk_subject = skp; cp = smk_parse_smack(object, len); if (cp == NULL) - return -1; + return -EINVAL; skp = smk_find_entry(cp); kfree(cp); if (skp == NULL) - return -1; + return -ENOENT; rule->smk_object = skp->smk_known; } @@ -366,56 +391,42 @@ static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule, * @data: string to be parsed, null terminated * @rule: Will be filled with Smack parsed rule * @import: if non-zero, import labels - * @change: if non-zero, data is from /smack/change-rule + * @tokens: numer of substrings expected in data * - * Returns 0 on success, -1 on failure - */ -static int smk_parse_long_rule(const char *data, struct smack_parsed_rule *rule, - int import, int change) -{ - char *subject; - char *object; - char *access1; - char *access2; - int datalen; - int rc = -1; - - /* This is inefficient */ - datalen = strlen(data); - - /* Our first element can be 64 + \0 with no spaces */ - subject = kzalloc(datalen + 1, GFP_KERNEL); - if (subject == NULL) - return -1; - object = kzalloc(datalen, GFP_KERNEL); - if (object == NULL) - goto free_out_s; - access1 = kzalloc(datalen, GFP_KERNEL); - if (access1 == NULL) - goto free_out_o; - access2 = kzalloc(datalen, GFP_KERNEL); - if (access2 == NULL) - goto free_out_a; - - if (change) { - if (sscanf(data, "%s %s %s %s", - subject, object, access1, access2) == 4) - rc = smk_fill_rule(subject, object, access1, access2, - rule, import, 0); - } else { - if (sscanf(data, "%s %s %s", subject, object, access1) == 3) - rc = smk_fill_rule(subject, object, access1, NULL, - rule, import, 0); + * Returns number of processed bytes on success, -1 on failure. + */ +static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, + int import, int tokens) +{ + ssize_t cnt = 0; + char *tok[4]; + int rc; + int i; + + /* + * Parsing the rule in-place, filling all white-spaces with '\0' + */ + for (i = 0; i < tokens; ++i) { + while (isspace(data[cnt])) + data[cnt++] = '\0'; + + if (data[cnt] == '\0') + /* Unexpected end of data */ + return -1; + + tok[i] = data + cnt; + + while (data[cnt] && !isspace(data[cnt])) + ++cnt; } + while (isspace(data[cnt])) + data[cnt++] = '\0'; - kfree(access2); -free_out_a: - kfree(access1); -free_out_o: - kfree(object); -free_out_s: - kfree(subject); - return rc; + while (i < 4) + tok[i++] = NULL; + + rc = smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0); + return rc == 0 ? cnt : rc; } #define SMK_FIXED24_FMT 0 /* Fixed 24byte label format */ @@ -445,12 +456,12 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, struct list_head *rule_list, struct mutex *rule_lock, int format) { - struct smack_known *skp; - struct smack_parsed_rule *rule; + struct smack_parsed_rule rule; char *data; - int datalen; - int rc = -EINVAL; - int load = 0; + int rc; + int trunc = 0; + int tokens; + ssize_t cnt = 0; /* * No partial writes. @@ -463,13 +474,16 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, /* * Minor hack for backward compatibility */ - if (count != SMK_OLOADLEN && count != SMK_LOADLEN) + if (count < SMK_OLOADLEN || count > SMK_LOADLEN) return -EINVAL; - datalen = SMK_LOADLEN; - } else - datalen = count + 1; + } else { + if (count >= PAGE_SIZE) { + count = PAGE_SIZE - 1; + trunc = 1; + } + } - data = kzalloc(datalen, GFP_KERNEL); + data = kmalloc(count + 1, GFP_KERNEL); if (data == NULL) return -ENOMEM; @@ -478,49 +492,49 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, goto out; } - rule = kzalloc(sizeof(*rule), GFP_KERNEL); - if (rule == NULL) { - rc = -ENOMEM; - goto out; - } - - if (format == SMK_LONG_FMT) { - /* - * Be sure the data string is terminated. - */ - data[count] = '\0'; - if (smk_parse_long_rule(data, rule, 1, 0)) - goto out_free_rule; - } else if (format == SMK_CHANGE_FMT) { - data[count] = '\0'; - if (smk_parse_long_rule(data, rule, 1, 1)) - goto out_free_rule; - } else { - /* - * More on the minor hack for backward compatibility - */ - if (count == (SMK_OLOADLEN)) - data[SMK_OLOADLEN] = '-'; - if (smk_parse_rule(data, rule, 1)) - goto out_free_rule; + /* + * In case of parsing only part of user buf, + * avoid having partial rule at the data buffer + */ + if (trunc) { + while (count > 0 && (data[count - 1] != '\n')) + --count; + if (count == 0) { + rc = -EINVAL; + goto out; + } } + data[count] = '\0'; + tokens = (format == SMK_CHANGE_FMT ? 4 : 3); + while (cnt < count) { + if (format == SMK_FIXED24_FMT) { + rc = smk_parse_rule(data, &rule, 1); + if (rc != 0) { + rc = -EINVAL; + goto out; + } + cnt = count; + } else { + rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens); + if (rc <= 0) { + rc = -EINVAL; + goto out; + } + cnt += rc; + } - if (rule_list == NULL) { - load = 1; - skp = smk_find_entry(rule->smk_subject); - rule_list = &skp->smk_rules; - rule_lock = &skp->smk_rules_lock; - } + if (rule_list == NULL) + rc = smk_set_access(&rule, &rule.smk_subject->smk_rules, + &rule.smk_subject->smk_rules_lock, 1); + else + rc = smk_set_access(&rule, rule_list, rule_lock, 0); - rc = smk_set_access(rule, rule_list, rule_lock, load); - if (rc == 0) { - rc = count; - goto out; + if (rc) + goto out; } -out_free_rule: - kfree(rule); + rc = cnt; out: kfree(data); return rc; @@ -579,13 +593,14 @@ static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max) * because you should expect to be able to write * anything you read back. */ - if (strlen(srp->smk_subject) >= max || strlen(srp->smk_object) >= max) + if (strlen(srp->smk_subject->smk_known) >= max || + strlen(srp->smk_object) >= max) return; if (srp->smk_access == 0) return; - seq_printf(s, "%s %s", srp->smk_subject, srp->smk_object); + seq_printf(s, "%s %s", srp->smk_subject->smk_known, srp->smk_object); seq_putc(s, ' '); @@ -599,6 +614,8 @@ static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max) seq_putc(s, 'a'); if (srp->smk_access & MAY_TRANSMUTE) seq_putc(s, 't'); + if (srp->smk_access & MAY_LOCK) + seq_putc(s, 'l'); seq_putc(s, '\n'); } @@ -738,9 +755,9 @@ static void smk_unlbl_ambient(char *oldambient) __func__, __LINE__, rc); } if (smack_net_ambient == NULL) - smack_net_ambient = smack_known_floor.smk_known; + smack_net_ambient = &smack_known_floor; - rc = netlbl_cfg_unlbl_map_add(smack_net_ambient, PF_INET, + rc = netlbl_cfg_unlbl_map_add(smack_net_ambient->smk_known, PF_INET, NULL, NULL, &nai); if (rc != 0) printk(KERN_WARNING "%s:%d add rc = %d\n", @@ -881,7 +898,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, if (format == SMK_FIXED24_FMT) rule += SMK_LABELLEN; else - rule += strlen(skp->smk_known); + rule += strlen(skp->smk_known) + 1; ret = sscanf(rule, "%d", &maplevel); if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL) @@ -901,7 +918,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, for (i = 0; i < catlen; i++) { rule += SMK_DIGITLEN; ret = sscanf(rule, "%u", &cat); - if (ret != 1 || cat > SMACK_CIPSO_MAXCATVAL) + if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM) goto out; smack_catset_bit(cat, mapcatset); @@ -1176,7 +1193,7 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, data[count] = '\0'; - rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%d %s", + rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s", &host[0], &host[1], &host[2], &host[3], &m, smack); if (rc != 6) { rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s", @@ -1535,11 +1552,12 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf, */ mutex_lock(&smack_ambient_lock); - asize = strlen(smack_net_ambient) + 1; + asize = strlen(smack_net_ambient->smk_known) + 1; if (cn >= asize) rc = simple_read_from_buffer(buf, cn, ppos, - smack_net_ambient, asize); + smack_net_ambient->smk_known, + asize); else rc = -EINVAL; @@ -1560,8 +1578,8 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf, static ssize_t smk_write_ambient(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { + struct smack_known *skp; char *oldambient; - char *smack = NULL; char *data; int rc = count; @@ -1577,16 +1595,16 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf, goto out; } - smack = smk_import(data, count); - if (smack == NULL) { + skp = smk_import_entry(data, count); + if (skp == NULL) { rc = -EINVAL; goto out; } mutex_lock(&smack_ambient_lock); - oldambient = smack_net_ambient; - smack_net_ambient = smack; + oldambient = smack_net_ambient->smk_known; + smack_net_ambient = skp; smk_unlbl_ambient(oldambient); mutex_unlock(&smack_ambient_lock); @@ -1603,7 +1621,7 @@ static const struct file_operations smk_ambient_ops = { }; /** - * smk_read_onlycap - read() for /smack/onlycap + * smk_read_onlycap - read() for smackfs/onlycap * @filp: file pointer, not actually used * @buf: where to put the result * @cn: maximum to send along @@ -1622,7 +1640,7 @@ static ssize_t smk_read_onlycap(struct file *filp, char __user *buf, return 0; if (smack_onlycap != NULL) - smack = smack_onlycap; + smack = smack_onlycap->smk_known; asize = strlen(smack) + 1; @@ -1633,7 +1651,7 @@ static ssize_t smk_read_onlycap(struct file *filp, char __user *buf, } /** - * smk_write_onlycap - write() for /smack/onlycap + * smk_write_onlycap - write() for smackfs/onlycap * @file: file pointer, not actually used * @buf: where to get the data from * @count: bytes sent @@ -1645,7 +1663,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char *data; - char *sp = smk_of_task(current->cred->security); + struct smack_known *skp = smk_of_task(current->cred->security); int rc = count; if (!smack_privileged(CAP_MAC_ADMIN)) @@ -1656,7 +1674,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, * explicitly for clarity. The smk_access() implementation * would use smk_access(smack_onlycap, MAY_WRITE) */ - if (smack_onlycap != NULL && smack_onlycap != sp) + if (smack_onlycap != NULL && smack_onlycap != skp) return -EPERM; data = kzalloc(count, GFP_KERNEL); @@ -1676,7 +1694,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, if (copy_from_user(data, buf, count) != 0) rc = -EFAULT; else - smack_onlycap = smk_import(data, count); + smack_onlycap = smk_import_entry(data, count); kfree(data); return rc; @@ -1839,7 +1857,6 @@ static ssize_t smk_user_access(struct file *file, const char __user *buf, { struct smack_parsed_rule rule; char *data; - char *cod; int res; data = simple_transaction_get(file, buf, count); @@ -1852,22 +1869,17 @@ static ssize_t smk_user_access(struct file *file, const char __user *buf, res = smk_parse_rule(data, &rule, 0); } else { /* - * Copy the data to make sure the string is terminated. + * simple_transaction_get() returns null-terminated data */ - cod = kzalloc(count + 1, GFP_KERNEL); - if (cod == NULL) - return -ENOMEM; - memcpy(cod, data, count); - cod[count] = '\0'; - res = smk_parse_long_rule(cod, &rule, 0, 0); - kfree(cod); + res = smk_parse_long_rule(data, &rule, 0, 3); } - if (res) + if (res >= 0) + res = smk_access(rule.smk_subject, rule.smk_object, + rule.smk_access1, NULL); + else if (res != -ENOENT) return -EINVAL; - res = smk_access(rule.smk_subject, rule.smk_object, rule.smk_access1, - NULL); data[0] = res == 0 ? '1' : '0'; data[1] = '\0'; @@ -2150,7 +2162,7 @@ static ssize_t smk_write_change_rule(struct file *file, const char __user *buf, /* * Must have privilege. */ - if (!capable(CAP_MAC_ADMIN)) + if (!smack_privileged(CAP_MAC_ADMIN)) return -EPERM; return smk_write_rules_list(file, buf, count, ppos, NULL, NULL, @@ -2165,12 +2177,151 @@ static const struct file_operations smk_change_rule_ops = { }; /** - * smk_fill_super - fill the /smackfs superblock + * smk_read_syslog - read() for smackfs/syslog + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_syslog(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + struct smack_known *skp; + ssize_t rc = -EINVAL; + int asize; + + if (*ppos != 0) + return 0; + + if (smack_syslog_label == NULL) + skp = &smack_known_star; + else + skp = smack_syslog_label; + + asize = strlen(skp->smk_known) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, skp->smk_known, + asize); + + return rc; +} + +/** + * smk_write_syslog - write() for smackfs/syslog + * @file: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_syslog(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)) + return -EPERM; + + data = kzalloc(count, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) + rc = -EFAULT; + else { + skp = smk_import_entry(data, count); + if (skp == NULL) + rc = -EINVAL; + else + smack_syslog_label = smk_import_entry(data, count); + } + + kfree(data); + return rc; +} + +static const struct file_operations smk_syslog_ops = { + .read = smk_read_syslog, + .write = smk_write_syslog, + .llseek = default_llseek, +}; + + +/** + * smk_read_ptrace - read() for /smack/ptrace + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_ptrace(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d\n", smack_ptrace_rule); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + return rc; +} + +/** + * smk_write_ptrace - write() for /smack/ptrace + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_ptrace(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[32]; + int i; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (*ppos != 0 || count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + if (i < SMACK_PTRACE_DEFAULT || i > SMACK_PTRACE_MAX) + return -EINVAL; + smack_ptrace_rule = i; + + return count; +} + +static const struct file_operations smk_ptrace_ops = { + .write = smk_write_ptrace, + .read = smk_read_ptrace, + .llseek = default_llseek, +}; + +/** + * smk_fill_super - fill the smackfs superblock * @sb: the empty superblock * @data: unused * @silent: unused * - * Fill in the well known entries for /smack + * Fill in the well known entries for the smack filesystem * * Returns 0 on success, an error code on failure */ @@ -2215,6 +2366,10 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) S_IRUGO|S_IWUSR}, [SMK_CHANGE_RULE] = { "change-rule", &smk_change_rule_ops, S_IRUGO|S_IWUSR}, + [SMK_SYSLOG] = { + "syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR}, + [SMK_PTRACE] = { + "ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR}, /* last one */ {""} }; |
