bplist: Fix possible out-of-bounds read in parse_array_node() with proper bounds checking

1 files changed, 12 insertions, 4 deletions

diff --git a/src/bplist.c b/src/bplist.c
index 2e32f70..a73f1ee 100644
--- a/src/bplist.c
+++ b/src/bplist.c
@@ -447,10 +447,11 @@ static plist_t parse_dict_node(struct bplist_data *bplist, const char** bnode, u
 static plist_t parse_array_node(struct bplist_data *bplist, const char** bnode, uint64_t size)
 {
     uint64_t j;
-    uint32_t str_j = 0;
-    uint32_t index1;
-
+    uint64_t str_j = 0;
+    uint64_t index1;
     plist_data_t data = plist_new_plist_data();
+    const char *const end_data = bplist->data + bplist->size;
+    const char *index1_ptr = NULL;
 
     data->type = PLIST_ARRAY;
     data->length = size;
@@ -459,7 +460,14 @@ static plist_t parse_array_node(struct bplist_data *bplist, const char** bnode,
 
     for (j = 0; j < data->length; j++) {
         str_j = j * bplist->ref_size;
-        index1 = UINT_TO_HOST((*bnode) + str_j, bplist->ref_size);
+        index1_ptr = (*bnode) + str_j;
+
+        if (index1_ptr < bplist->data || index1_ptr + bplist->ref_size >= end_data) {
+            plist_free(node);
+            return NULL;
+        }
+
+        index1 = UINT_TO_HOST(index1_ptr, bplist->ref_size);
 
         if (index1 >= bplist->num_objects) {
             plist_free(node);