From 61922b26e0a7a36a9367590a82c3871feb855fc8 Mon Sep 17 00:00:00 2001 From: Wenlin Kang Date: Tue, 1 Sep 2020 14:11:30 -0700 Subject: lua: fix CVE-2020-15945 Source: openembedded.org MR: 104897 Type: Security Fix Disposition: Backport from https://git.openembedded.org/meta-openembedded gatesgarth ChangeID: 6c43941d116bbb9f0d62ca5376da24ae03eb9eab Description: Fixes CVE-2020-15945 Backport with modifications to apply successfully. Signed-off-by: Wenlin Kang Signed-off-by: Joe Slater Signed-off-by: Khem Raj Signed-off-by: Armin Kuster Signed-off-by: Armin Kuster --- .../recipes-devtools/lua/lua/CVE-2020-15945.patch | 167 +++++++++++++++++++++ meta-oe/recipes-devtools/lua/lua_5.3.5.bb | 1 + 2 files changed, 168 insertions(+) create mode 100644 meta-oe/recipes-devtools/lua/lua/CVE-2020-15945.patch (limited to 'meta-oe') diff --git a/meta-oe/recipes-devtools/lua/lua/CVE-2020-15945.patch b/meta-oe/recipes-devtools/lua/lua/CVE-2020-15945.patch new file mode 100644 index 0000000000..89ce491487 --- /dev/null +++ b/meta-oe/recipes-devtools/lua/lua/CVE-2020-15945.patch @@ -0,0 +1,167 @@ +From d8d344365945a534f700c82c5dd26f704f89fef3 Mon Sep 17 00:00:00 2001 +From: Roberto Ierusalimschy +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 +Signed-off-by: Joe Slater + +--- + 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 + diff --git a/meta-oe/recipes-devtools/lua/lua_5.3.5.bb b/meta-oe/recipes-devtools/lua/lua_5.3.5.bb index d3461b06de..4f89579c78 100644 --- a/meta-oe/recipes-devtools/lua/lua_5.3.5.bb +++ b/meta-oe/recipes-devtools/lua/lua_5.3.5.bb @@ -8,6 +8,7 @@ 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 \ " # if no test suite matches PV release of Lua exactly, download the suite for the closest Lua release. -- cgit 1.2.3-korg