lua: Backport fix for CVE-2022-33099

Fixes stack overflow while handling recurring errors in Lua-stack

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 62 insertions, 0 deletions

diff --git a/meta/recipes-devtools/lua/lua/CVE-2022-33099.patch b/meta/recipes-devtools/lua/lua/CVE-2022-33099.patch
new file mode 100644
index 0000000000..fe7b6065c2
--- /dev/null
+++ b/meta/recipes-devtools/lua/lua/CVE-2022-33099.patch
@@ -0,0 +1,61 @@
+From 42d40581dd919fb134c07027ca1ce0844c670daf Mon Sep 17 00:00:00 2001
+From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
+Date: Fri, 20 May 2022 13:14:33 -0300
+Subject: [PATCH] Save stack space while handling errors
+
+Because error handling (luaG_errormsg) uses slots from EXTRA_STACK,
+and some errors can recur (e.g., string overflow while creating an
+error message in 'luaG_runerror', or a C-stack overflow before calling
+the message handler), the code should use stack slots with parsimony.
+
+This commit fixes the bug "Lua-stack overflow when C stack overflows
+while handling an error".
+
+CVE: CVE-2022-33099
+
+Upstream-Status: Backport [https://github.com/lua/lua/commit/42d40581dd919fb134c07027ca1ce0844c670daf]
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ ldebug.c | 5 ++++-
+ lvm.c    | 6 ++++--
+ 2 files changed, 8 insertions(+), 3 deletions(-)
+
+--- a/src/ldebug.c
++++ b/src/ldebug.c
+@@ -824,8 +824,11 @@ l_noret luaG_runerror (lua_State *L, con
+   va_start(argp, fmt);
+   msg = luaO_pushvfstring(L, fmt, argp);  /* format message */
+   va_end(argp);
+-  if (isLua(ci))  /* if Lua function, add source:line information */
++  if (isLua(ci)) {  /* if Lua function, add source:line information */
+     luaG_addinfo(L, msg, ci_func(ci)->p->source, getcurrentline(ci));
++    setobjs2s(L, L->top - 2, L->top - 1);  /* remove 'msg' from the stack */
++    L->top--;
++  }
+   luaG_errormsg(L);
+ }
+ 
+--- a/src/lvm.c
++++ b/src/lvm.c
+@@ -656,8 +656,10 @@ void luaV_concat (lua_State *L, int tota
+       /* collect total length and number of strings */
+       for (n = 1; n < total && tostring(L, s2v(top - n - 1)); n++) {
+         size_t l = vslen(s2v(top - n - 1));
+-        if (l_unlikely(l >= (MAX_SIZE/sizeof(char)) - tl))
++        if (l_unlikely(l >= (MAX_SIZE/sizeof(char)) - tl)) {
++          L->top = top - total;  /* pop strings to avoid wasting stack */
+           luaG_runerror(L, "string length overflow");
++        }
+         tl += l;
+       }
+       if (tl <= LUAI_MAXSHORTLEN) {  /* is result a short string? */
+@@ -672,7 +674,7 @@ void luaV_concat (lua_State *L, int tota
+       setsvalue2s(L, top - n, ts);  /* create result */
+     }
+     total -= n-1;  /* got 'n' strings to create 1 new */
+-    L->top -= n-1;  /* popped 'n' strings and pushed one */
++    L->top = top - (n - 1);  /* popped 'n' strings and pushed one */
+   } while (total > 1);  /* repeat until only 1 result left */
+ }
+ 
diff --git a/meta/recipes-devtools/lua/lua_5.4.4.bb b/meta/recipes-devtools/lua/lua_5.4.4.bb
index 6f2cea5314..0b2e754b31 100644
--- a/meta/recipes-devtools/lua/lua_5.4.4.bb
+++ b/meta/recipes-devtools/lua/lua_5.4.4.bb
@@ -7,6 +7,7 @@ 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 \
+           file://CVE-2022-33099.patch \
            ${@bb.utils.contains('DISTRO_FEATURES', 'ptest', 'http://www.lua.org/tests/lua-${PV_testsuites}-tests.tar.gz;name=tarballtest file://run-ptest ', '', d)} \
            "