Bug: Use after free in 'luaV_finishset'

If a metatable is a weak table, its __newindex field could be collected
by an emergency collection while being used in 'luaV_finishset'. (This
bug has similarities with bug 5.3.2-1, fixed in commit a272fa66.)

1 files changed, 13 insertions, 0 deletions

diff --git a/testes/events.lua b/testes/events.lua
index 8d8563b9..def13dc8 100644
--- a/testes/events.lua
+++ b/testes/events.lua
@@ -370,6 +370,19 @@ x = 0 .."a".."b"..c..d.."e".."f".."g"
 assert(x.val == "0abcdefg")
 
 
+do
+  -- bug since 5.4.1
+  local mt = setmetatable({__newindex={}}, {__mode='v'})
+  local t = setmetatable({}, mt)
+
+  if T then T.allocfailnext() end
+
+  -- seg. fault
+  for i=1, 10 do t[i] = 1 end
+end
+
+
+
 -- concat metamethod x numbers (bug in 5.1.1)
 c = {}
 local x