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-rw-r--r--security/smack/smackfs.c167
1 files changed, 82 insertions, 85 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index a07e93f00a0..80f4b4a4572 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,
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-22 18:36:20 +0000