libcnary: [BUGFIX] Set list->end to NULL when removing last and only element from list
This prevents a UaF in node_list_add. The issue became visible after removing
the last (and only) item from a PLIST_DICT or PLIST_ARRAY node, and then
adding a new item - the item will not make it into the actual dictionary or
array because the list->end pointer points to invalid memory, effectively
causing memory corruption.
diff --git a/libcnary/node_list.c b/libcnary/node_list.c
index a45457d..b0dca0a 100644
--- a/libcnary/node_list.c
+++ b/libcnary/node_list.c
@@ -142,6 +142,8 @@
// we just removed the first element
if (newnode) {
newnode->prev = NULL;
+ } else {
+ list->end = NULL;
}
list->begin = newnode;
}
