diff options
| -rw-r--r-- | security/smack/smackfs.c | 167 |
1 files changed, 82 insertions, 85 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index a07e93f00a0f..80f4b4a45725 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -368,56 +368,43 @@ 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 + * Returns number of processed bytes on success, -1 on failure. */ -static int smk_parse_long_rule(const char *data, struct smack_parsed_rule *rule, - int import, int change) +static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, + int import, int tokens) { - char *subject; - char *object; - char *access1; - char *access2; - int datalen; - int rc = -1; + ssize_t cnt = 0; + char *tok[4]; + int i; - /* This is inefficient */ - datalen = strlen(data); + /* + * Parsing the rule in-place, filling all white-spaces with '\0' + */ + for (i = 0; i < tokens; ++i) { + while (isspace(data[cnt])) + data[cnt++] = '\0'; - /* 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); + 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; + + if (smk_fill_rule(tok[0], tok[1], tok[2], tok[3], rule, import, 0)) + return -1; + + return cnt; } #define SMK_FIXED24_FMT 0 /* Fixed 24byte label format */ @@ -449,9 +436,10 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, { 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. @@ -466,11 +454,14 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, */ 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; @@ -479,36 +470,49 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, 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; - } else if (format == SMK_CHANGE_FMT) { - data[count] = '\0'; - if (smk_parse_long_rule(data, &rule, 1, 1)) - goto out; - } else { - /* - * More on the minor hack for backward compatibility - */ - if (count == (SMK_OLOADLEN)) - data[SMK_OLOADLEN] = '-'; - if (smk_parse_rule(data, &rule, 1)) + /* + * 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; + } } - if (rule_list == NULL) { - load = 1; - rule_list = &rule.smk_subject->smk_rules; - rule_lock = &rule.smk_subject->smk_rules_lock; + 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) + 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); + + if (rc) + goto out; } - rc = smk_set_access(&rule, rule_list, rule_lock, load); - if (rc == 0) - rc = count; + rc = cnt; out: kfree(data); return rc; @@ -1829,7 +1833,6 @@ 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); @@ -1842,18 +1845,12 @@ 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) return -EINVAL; res = smk_access(rule.smk_subject, rule.smk_object, |