lua: fix CVE-2022-28805

singlevar in lparser.c in Lua through 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.

https://nvd.nist.gov/vuln/detail/CVE-2022-28805

(From OE-Core rev: d2ba3b8850d461bc7b773240cdf15b22b31a3f9e)

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 27 insertions, 0 deletions

diff --git a/meta/recipes-devtools/lua/lua/CVE-2022-28805.patch b/meta/recipes-devtools/lua/lua/CVE-2022-28805.patch
new file mode 100644
index 0000000000..3680c715a7
--- /dev/null
+++ b/meta/recipes-devtools/lua/lua/CVE-2022-28805.patch
@@ -0,0 +1,26 @@
+From 1f3c6f4534c6411313361697d98d1145a1f030fa Mon Sep 17 00:00:00 2001
+From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
+Date: Tue, 15 Feb 2022 12:28:46 -0300
+Subject: [PATCH] Bug: Lua can generate wrong code when _ENV is <const>
+
+CVE: CVE-2022-28805
+
+Upstream-Status: Backport [https://github.com/lua/lua/commit/1f3c6f4534c6411313361697d98d1145a1f030fa]
+
+Signed-off-by: Steve Sakoman <steve@sakoman.com>
+---
+ src/lparser.c         |  1 +
+ 1 files changed, 1 insertions(+)
+
+diff --git a/src/lparser.c b/src/lparser.c
+index 3abe3d751..a5cd55257 100644
+--- a/src/lparser.c
++++ b/src/lparser.c
+@@ -468,6 +468,7 @@ static void singlevar (LexState *ls, expdesc *var) {
+     expdesc key;
+     singlevaraux(fs, ls->envn, var, 1);  /* get environment variable */
+     lua_assert(var->k != VVOID);  /* this one must exist */
++    luaK_exp2anyregup(fs, var);  /* but could be a constant */
+     codestring(&key, varname);  /* key is variable name */
+     luaK_indexed(fs, var, &key);  /* env[varname] */
+   }
diff --git a/meta/recipes-devtools/lua/lua_5.4.4.bb b/meta/recipes-devtools/lua/lua_5.4.4.bb
index f50328ecfd..d704841378 100644
--- a/meta/recipes-devtools/lua/lua_5.4.4.bb
+++ b/meta/recipes-devtools/lua/lua_5.4.4.bb
@@ -6,6 +6,7 @@ HOMEPAGE = "http://www.lua.org/"
 
 SRC_URI = "http://www.lua.org/ftp/lua-${PV}.tar.gz;name=tarballsrc \
            file://lua.pc.in \
+           file://CVE-2022-28805.patch \
            ${@bb.utils.contains('DISTRO_FEATURES', 'ptest', 'http://www.lua.org/tests/lua-${PV_testsuites}-tests.tar.gz;name=tarballtest file://run-ptest ', '', d)} \
            "