Remove patch that produces a segfault in the ptest of lua

The patch file CVE-2020-15945.patch does cause a segfault in the lua ptest (db.lua test).
According to upstream developers the patch is not correct and causes the segfault.

Reproduce: build core-image-minimal with lua and ptest-pkgs on .
Run: ptest-runner lua

This test passes if the patch is removed.

Please also backport to dunfell as well.

Signed-off-by: Jan-Simon Moeller <dl9pf@gmx.de>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-devtools/lua/lua/CVE-2020-15945.patch

@@ -1,167 +0,0 @@
-From d8d344365945a534f700c82c5dd26f704f89fef3 Mon Sep 17 00:00:00 2001
-From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
-Date: Wed, 5 Aug 2020 16:59:58 +0800
-Subject: [PATCH] Fixed bug: invalid 'oldpc' when returning to a function
-
-The field 'L->oldpc' is not always updated when control returns to a
-function; an invalid value can seg. fault when computing 'changedline'.
-(One example is an error in a finalizer; control can return to
-'luaV_execute' without executing 'luaD_poscall'.) Instead of trying to
-fix all possible corner cases, it seems safer to be resilient to invalid
-values for 'oldpc'. Valid but wrong values at most cause an extra call
-to a line hook.
-
-CVE: CVE-2020-15945
-
-[Adjust the code to be applicable to the tree]
-
-Upstream-Status: Backport [https://github.com/lua/lua/commit/a2195644d89812e5b157ce7bac35543e06db05e3]
-
-Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
-Signed-off-by: Joe Slater <joe.slater@@windriver.com>
-
----
- src/ldebug.c | 30 +++++++++++++++---------------
- src/ldebug.h |  4 ++++
- src/ldo.c    |  2 +-
- src/lstate.c |  1 +
- src/lstate.h |  2 +-
- 5 files changed, 22 insertions(+), 17 deletions(-)
-
-diff --git a/src/ldebug.c b/src/ldebug.c
-index 239affb..832b16c 100644
---- a/src/ldebug.c
-+++ b/src/ldebug.c
-@@ -34,9 +34,8 @@
- #define noLuaClosure(f)		((f) == NULL || (f)->c.tt == LUA_TCCL)
- 
- 
--/* Active Lua function (given call info) */
--#define ci_func(ci)		(clLvalue((ci)->func))
--
-+/* inverse of 'pcRel' */
-+#define invpcRel(pc, p)                ((p)->code + (pc) + 1)
- 
- static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
-                                     const char **name);
-@@ -71,20 +70,18 @@ static void swapextra (lua_State *L) {
- 
- /*
- ** This function can be called asynchronously (e.g. during a signal).
--** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
--** 'resethookcount') are for debug only, and it is no problem if they
--** get arbitrary values (causes at most one wrong hook call). 'hookmask'
--** is an atomic value. We assume that pointers are atomic too (e.g., gcc
--** ensures that for all platforms where it runs). Moreover, 'hook' is
--** always checked before being called (see 'luaD_hook').
-+** Fields 'basehookcount' and 'hookcount' (set by 'resethookcount')
-+** are for debug only, and it is no problem if they get arbitrary
-+** values (causes at most one wrong hook call). 'hookmask' is an atomic
-+** value. We assume that pointers are atomic too (e.g., gcc ensures that
-+** for all platforms where it runs). Moreover, 'hook' is always checked
-+** before being called (see 'luaD_hook').
- */
- LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
-   if (func == NULL || mask == 0) {  /* turn off hooks? */
-     mask = 0;
-     func = NULL;
-   }
--  if (isLua(L->ci))
--    L->oldpc = L->ci->u.l.savedpc;
-   L->hook = func;
-   L->basehookcount = count;
-   resethookcount(L);
-@@ -665,7 +662,10 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
- void luaG_traceexec (lua_State *L) {
-   CallInfo *ci = L->ci;
-   lu_byte mask = L->hookmask;
-+  const Proto *p = ci_func(ci)->p;
-   int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
-+  /* 'L->oldpc' may be invalid; reset it in this case */
-+  int oldpc = (L->oldpc < p->sizecode) ? L->oldpc : 0;
-   if (counthook)
-     resethookcount(L);  /* reset count */
-   else if (!(mask & LUA_MASKLINE))
-@@ -677,15 +677,15 @@ void luaG_traceexec (lua_State *L) {
-   if (counthook)
-     luaD_hook(L, LUA_HOOKCOUNT, -1);  /* call count hook */
-   if (mask & LUA_MASKLINE) {
--    Proto *p = ci_func(ci)->p;
-     int npc = pcRel(ci->u.l.savedpc, p);
-     int newline = getfuncline(p, npc);
-     if (npc == 0 ||  /* call linehook when enter a new function, */
--        ci->u.l.savedpc <= L->oldpc ||  /* when jump back (loop), or when */
--        newline != getfuncline(p, pcRel(L->oldpc, p)))  /* enter a new line */
-+        ci->u.l.savedpc <= invpcRel(oldpc, p) ||  /* when jump back (loop), or when */
-+        newline != getfuncline(p, oldpc))  /* enter a new line */
-       luaD_hook(L, LUA_HOOKLINE, newline);  /* call line hook */
-+
-+    L->oldpc = npc;  /* 'pc' of last call to line hook */
-   }
--  L->oldpc = ci->u.l.savedpc;
-   if (L->status == LUA_YIELD) {  /* did hook yield? */
-     if (counthook)
-       L->hookcount = 1;  /* undo decrement to zero */
-diff --git a/src/ldebug.h b/src/ldebug.h
-index 0e31546..c224cc4 100644
---- a/src/ldebug.h
-+++ b/src/ldebug.h
-@@ -13,6 +13,10 @@
- 
- #define pcRel(pc, p)	(cast(int, (pc) - (p)->code) - 1)
- 
-+/* Active Lua function (given call info) */
-+#define ci_func(ci)            (clLvalue((ci)->func))
-+
-+
- #define getfuncline(f,pc)	(((f)->lineinfo) ? (f)->lineinfo[pc] : -1)
- 
- #define resethookcount(L)	(L->hookcount = L->basehookcount)
-diff --git a/src/ldo.c b/src/ldo.c
-index 90b695f..f66ac1a 100644
---- a/src/ldo.c
-+++ b/src/ldo.c
-@@ -382,7 +382,7 @@ int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
-       luaD_hook(L, LUA_HOOKRET, -1);
-       firstResult = restorestack(L, fr);
-     }
--    L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
-+    L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p);  /* 'oldpc' for caller function */
-   }
-   res = ci->func;  /* res == final position of 1st result */
-   L->ci = ci->previous;  /* back to caller */
-diff --git a/src/lstate.c b/src/lstate.c
-index 9194ac3..3573e36 100644
---- a/src/lstate.c
-+++ b/src/lstate.c
-@@ -236,6 +236,7 @@ static void preinit_thread (lua_State *L, global_State *g) {
-   L->nny = 1;
-   L->status = LUA_OK;
-   L->errfunc = 0;
-+  L->oldpc = 0;
- }
- 
- 
-diff --git a/src/lstate.h b/src/lstate.h
-index a469466..d75eadf 100644
---- a/src/lstate.h
-+++ b/src/lstate.h
-@@ -164,7 +164,6 @@ struct lua_State {
-   StkId top;  /* first free slot in the stack */
-   global_State *l_G;
-   CallInfo *ci;  /* call info for current function */
--  const Instruction *oldpc;  /* last pc traced */
-   StkId stack_last;  /* last free slot in the stack */
-   StkId stack;  /* stack base */
-   UpVal *openupval;  /* list of open upvalues in this stack */
-@@ -174,6 +173,7 @@ struct lua_State {
-   CallInfo base_ci;  /* CallInfo for first level (C calling Lua) */
-   volatile lua_Hook hook;
-   ptrdiff_t errfunc;  /* current error handling function (stack index) */
-+  int oldpc;  /* last pc traced */
-   int stacksize;
-   int basehookcount;
-   int hookcount;
--- 
-2.13.3
-

meta-oe/recipes-devtools/lua/lua_5.3.6.bb

@@ -8,7 +8,6 @@ SRC_URI = "http://www.lua.org/ftp/lua-${PV}.tar.gz;name=tarballsrc \
            file://lua.pc.in \
            file://0001-Allow-building-lua-without-readline-on-Linux.patch \
            file://CVE-2020-15888.patch \
-           file://CVE-2020-15945.patch \
            file://0001-Fixed-bug-barriers-cannot-be-active-during-sweep.patch \
            "