1 files changed, 77 insertions, 101 deletions

diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index 39475fb455bc..2fe459df3c85 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -218,9 +218,7 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
 /*
  * Set the MLS fields in the security context structure
  * `context' based on the string representation in
- * the string `*scontext'.  Update `*scontext' to
- * point to the end of the string representation of
- * the MLS fields.
+ * the string `scontext'.
  *
  * This function modifies the string in place, inserting
  * NULL characters to terminate the MLS fields.
@@ -235,22 +233,21 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
  */
 int mls_context_to_sid(struct policydb *pol,
                        char oldc,
-                       char **scontext,
+                       char *scontext,
                        struct context *context,
                        struct sidtab *s,
                        u32 def_sid)
 {
-
-        char delim;
-        char *scontextp, *p, *rngptr;
+        char *sensitivity, *cur_cat, *next_cat, *rngptr;
         struct level_datum *levdatum;
         struct cat_datum *catdatum, *rngdatum;
-        int l, rc = -EINVAL;
+        int l, rc, i;
+        char *rangep[2];
 
         if (!pol->mls_enabled) {
-                if (def_sid != SECSID_NULL && oldc)
-                        *scontext += strlen(*scontext) + 1;
-                return 0;
+                if ((def_sid != SECSID_NULL && oldc) || (*scontext) == '\0')
+                        return 0;
+                return -EINVAL;
         }
 
         /*
@@ -261,113 +258,94 @@ int mls_context_to_sid(struct policydb *pol,
                 struct context *defcon;
 
                 if (def_sid == SECSID_NULL)
-                        goto out;
+                        return -EINVAL;
 
                 defcon = sidtab_search(s, def_sid);
                 if (!defcon)
-                        goto out;
+                        return -EINVAL;
 
-                rc = mls_context_cpy(context, defcon);
-                goto out;
+                return mls_context_cpy(context, defcon);
         }
 
-        /* Extract low sensitivity. */
-        scontextp = p = *scontext;
-        while (*p && *p != ':' && *p != '-')
-                p++;
-
-        delim = *p;
-        if (delim != '\0')
-                *p++ = '\0';
+        /*
+         * If we're dealing with a range, figure out where the two parts
+         * of the range begin.
+         */
+        rangep[0] = scontext;
+        rangep[1] = strchr(scontext, '-');
+        if (rangep[1]) {
+                rangep[1][0] = '\0';
+                rangep[1]++;
+        }
 
+        /* For each part of the range: */
         for (l = 0; l < 2; l++) {
-                levdatum = hashtab_search(pol->p_levels.table, scontextp);
-                if (!levdatum) {
-                        rc = -EINVAL;
-                        goto out;
-                }
+                /* Split sensitivity and category set. */
+                sensitivity = rangep[l];
+                if (sensitivity == NULL)
+                        break;
+                next_cat = strchr(sensitivity, ':');
+                if (next_cat)
+                        *(next_cat++) = '\0';
 
+                /* Parse sensitivity. */
+                levdatum = hashtab_search(pol->p_levels.table, sensitivity);
+                if (!levdatum)
+                        return -EINVAL;
                 context->range.level[l].sens = levdatum->level->sens;
 
-                if (delim == ':') {
-                        /* Extract category set. */
-                        while (1) {
-                                scontextp = p;
-                                while (*p && *p != ',' && *p != '-')
-                                        p++;
-                                delim = *p;
-                                if (delim != '\0')
-                                        *p++ = '\0';
-
-                                /* Separate into range if exists */
-                                rngptr = strchr(scontextp, '.');
-                                if (rngptr != NULL) {
-                                        /* Remove '.' */
-                                        *rngptr++ = '\0';
-                                }
+                /* Extract category set. */
+                while (next_cat != NULL) {
+                        cur_cat = next_cat;
+                        next_cat = strchr(next_cat, ',');
+                        if (next_cat != NULL)
+                                *(next_cat++) = '\0';
+
+                        /* Separate into range if exists */
+                        rngptr = strchr(cur_cat, '.');
+                        if (rngptr != NULL) {
+                                /* Remove '.' */
+                                *rngptr++ = '\0';
+                        }
 
-                                catdatum = hashtab_search(pol->p_cats.table,
-                                                          scontextp);
-                                if (!catdatum) {
-                                        rc = -EINVAL;
-                                        goto out;
-                                }
+                        catdatum = hashtab_search(pol->p_cats.table, cur_cat);
+                        if (!catdatum)
+                                return -EINVAL;
 
-                                rc = ebitmap_set_bit(&context->range.level[l].cat,
-                                                     catdatum->value - 1, 1);
-                                if (rc)
-                                        goto out;
-
-                                /* If range, set all categories in range */
-                                if (rngptr) {
-                                        int i;
-
-                                        rngdatum = hashtab_search(pol->p_cats.table, rngptr);
-                                        if (!rngdatum) {
-                                                rc = -EINVAL;
-                                                goto out;
-                                        }
-
-                                        if (catdatum->value >= rngdatum->value) {
-                                                rc = -EINVAL;
-                                                goto out;
-                                        }
-
-                                        for (i = catdatum->value; i < rngdatum->value; i++) {
-                                                rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1);
-                                                if (rc)
-                                                        goto out;
-                                        }
-                                }
+                        rc = ebitmap_set_bit(&context->range.level[l].cat,
+                                             catdatum->value - 1, 1);
+                        if (rc)
+                                return rc;
+
+                        /* If range, set all categories in range */
+                        if (rngptr == NULL)
+                                continue;
+
+                        rngdatum = hashtab_search(pol->p_cats.table, rngptr);
+                        if (!rngdatum)
+                                return -EINVAL;
+
+                        if (catdatum->value >= rngdatum->value)
+                                return -EINVAL;
 
-                                if (delim != ',')
-                                        break;
+                        for (i = catdatum->value; i < rngdatum->value; i++) {
+                                rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1);
+                                if (rc)
+                                        return rc;
                         }
                 }
-                if (delim == '-') {
-                        /* Extract high sensitivity. */
-                        scontextp = p;
-                        while (*p && *p != ':')
-                                p++;
-
-                        delim = *p;
-                        if (delim != '\0')
-                                *p++ = '\0';
-                } else
-                        break;
         }
 
-        if (l == 0) {
+        /* If we didn't see a '-', the range start is also the range end. */
+        if (rangep[1] == NULL) {
                 context->range.level[1].sens = context->range.level[0].sens;
                 rc = ebitmap_cpy(&context->range.level[1].cat,
                                  &context->range.level[0].cat);
                 if (rc)
-                        goto out;
+                        return rc;
         }
-        *scontext = ++p;
-        rc = 0;
-out:
-        return rc;
+
+        return 0;
 }
 
 /*
@@ -379,21 +357,19 @@ out:
 int mls_from_string(struct policydb *p, char *str, struct context *context,
                     gfp_t gfp_mask)
 {
-        char *tmpstr, *freestr;
+        char *tmpstr;
         int rc;
 
         if (!p->mls_enabled)
                 return -EINVAL;
 
-        /* we need freestr because mls_context_to_sid will change
-           the value of tmpstr */
-        tmpstr = freestr = kstrdup(str, gfp_mask);
+        tmpstr = kstrdup(str, gfp_mask);
         if (!tmpstr) {
                 rc = -ENOMEM;
         } else {
-                rc = mls_context_to_sid(p, ':', &tmpstr, context,
+                rc = mls_context_to_sid(p, ':', tmpstr, context,
                                         NULL, SECSID_NULL);
-                kfree(freestr);
+                kfree(tmpstr);
         }
 
         return rc;