uci: fix a potential use-after-free in uci_set()

[project/uci.git] / ucimap.c

diff --git a/ucimap.c b/ucimap.c
index 52c920b..b4f9518 100644 (file)
--- a/ucimap.c
+++ b/ucimap.c
@@ -9,11 +9,11 @@
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ * GNU Lesser General Public License for more details.
  */
 
 /*
- * This file contains ucimap, an API for mapping UCI to C data structures 
+ * This file contains ucimap, an API for mapping UCI to C data structures
  */
 
 #include <strings.h>
@@ -59,23 +59,13 @@ struct ucimap_fixup {
 static inline bool
 ucimap_is_alloc(enum ucimap_type type)
 {
-       switch(type & UCIMAP_SUBTYPE) {
-       case UCIMAP_STRING:
-               return true;
-       default:
-               return false;
-       }
+       return (type & UCIMAP_SUBTYPE) == UCIMAP_STRING;
 }
 
 static inline bool
 ucimap_is_fixup(enum ucimap_type type)
 {
-       switch(type & UCIMAP_SUBTYPE) {
-       case UCIMAP_SECTION:
-               return true;
-       default:
-               return false;
-       }
+       return (type & UCIMAP_SUBTYPE) == UCIMAP_SECTION;
 }
 
 static inline bool
@@ -172,9 +162,10 @@ ucimap_free_section(struct uci_map *map, struct ucimap_section_data *sd)
 void
 ucimap_cleanup(struct uci_map *map)
 {
-       struct ucimap_section_data *sd;
+       struct ucimap_section_data *sd, *sd_next;
 
-       for (sd = map->sdata; sd; sd = sd->next) {
+       for (sd = map->sdata; sd; sd = sd_next) {
+               sd_next = sd->next;
                ucimap_free_section(map, sd);
        }
 }
@@ -217,7 +208,6 @@ static bool
 ucimap_handle_fixup(struct uci_map *map, struct ucimap_fixup *f)
 {
        void *ptr = ucimap_find_section(map, f);
-       struct ucimap_list *list;
        union ucimap_data *data;
 
        if (!ptr)
@@ -228,7 +218,6 @@ ucimap_handle_fixup(struct uci_map *map, struct ucimap_fixup *f)
                f->data->ptr = ptr;
                break;
        case UCIMAP_LIST:
-               list = f->data->list;
                data = ucimap_list_append(f->data->list);
                if (!data)
                        return false;
@@ -286,6 +275,8 @@ ucimap_resize_list(struct ucimap_section_data *sd, struct ucimap_list **list, in
 
        if (!*list) {
                new = calloc(1, size);
+               if (!new)
+                       return -ENOMEM;
 
                ucimap_add_alloc(sd, new);
                goto set;
@@ -304,6 +295,9 @@ realloc:
                offset = (items - (*list)->size) * sizeof(union ucimap_data);
 
        a->ptr = realloc(a->ptr, size);
+       if (!a->ptr)
+               return -ENOMEM;
+
        if (offset)
                memset((char *) a->ptr + offset, 0, size - offset);
        new = a->ptr;
@@ -320,6 +314,7 @@ ucimap_add_fixup(struct ucimap_section_data *sd, union ucimap_data *data, struct
        struct ucimap_fixup *f, tmp;
        struct uci_map *map = sd->map;
 
+       tmp.next = NULL;
        tmp.sm = om->data.sm;
        tmp.name = str;
        tmp.type = om->type;
@@ -718,8 +713,8 @@ ucimap_parse_section(struct uci_map *map, struct uci_sectionmap *sm, struct ucim
        return 0;
 
 error_mem:
-       if (sd->allocmap)
-               free(sd->allocmap);
+       free(sd->alloc_custom);
+       free(sd->allocmap);
        free(sd);
        return UCI_ERR_MEM;
 
@@ -894,6 +889,7 @@ ucimap_parse(struct uci_map *map, struct uci_package *pkg)
                        } else {
                                sd = malloc(sm->alloc_len);
                                memset(sd, 0, sm->alloc_len);
+                               sd = ucimap_ptr_section(sm, sd);
                        }
                        if (!sd)
                                continue;