singlevar in lparser.c in Lua from (including) 5.4.0 up to (excluding) 5.4.4 lacks a certain luaK_exp2anyregup call, leading to a heap-based buffer over-read that might affect a system that compiles untrusted Lua code.
References
- https://github.com/lua/lua/commit/1f3c6f4534c6411313361697d98d1145a1f030fa
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJNJ66IFDUKWJJZXHGOLRGIA3HWWC36R/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UHYZOEFDVLVAD6EEP4CDW6DNONIVVHPA/
- https://lua-users.org/lists/lua-l/2022-02/msg00001.html
- https://lua-users.org/lists/lua-l/2022-02/msg00070.html
- https://lua-users.org/lists/lua-l/2022-04/msg00009.html
- https://security.gentoo.org/glsa/202305-23