| From 6298903e35217ab69c279056f925fb72900ce0b7 Mon Sep 17 00:00:00 2001 |
| From: Roberto Ierusalimschy <roberto@inf.puc-rio.br> |
| Date: Mon, 6 Jul 2020 12:11:54 -0300 |
| Subject: [PATCH] Keep minimum size when shrinking a stack |
| |
| When shrinking a stack (during GC), do not make it smaller than the |
| initial stack size. |
| --- |
| ldo.c | 5 ++--- |
| 1 file changed, 2 insertions(+), 3 deletions(-) |
| ==== end of original header ==== |
| |
| CVE: CVE-2020-15888 |
| |
| Upstream-Status: backport [https://github.com/lua/lua.git] |
| |
| Signed-off-by: Joe Slater <joe.slater@windriver.com> |
| |
| ==== |
| diff --git a/ldo.c b/ldo.c |
| index c563b1d9..a89ac010 100644 |
| --- a/src/ldo.c |
| +++ b/src/ldo.c |
| @@ -220,7 +220,7 @@ static int stackinuse (lua_State *L) { |
| |
| void luaD_shrinkstack (lua_State *L) { |
| int inuse = stackinuse(L); |
| - int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK; |
| + int goodsize = inuse + BASIC_STACK_SIZE; |
| if (goodsize > LUAI_MAXSTACK) |
| goodsize = LUAI_MAXSTACK; /* respect stack limit */ |
| if (L->stacksize > LUAI_MAXSTACK) /* had been handling stack overflow? */ |
| @@ -229,8 +229,7 @@ void luaD_shrinkstack (lua_State *L) { |
| luaE_shrinkCI(L); /* shrink list */ |
| /* if thread is currently not handling a stack overflow and its |
| good size is smaller than current size, shrink its stack */ |
| - if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) && |
| - goodsize < L->stacksize) |
| + if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) && goodsize < L->stacksize) |
| luaD_reallocstack(L, goodsize); |
| else /* don't change stack */ |
| condmovestack(L,{},{}); /* (change only for debugging) */ |
| -- |
| 2.17.1 |
| |