mujs/0004-Bug-706057-Fix-use-after-free-in-getOwnPropertyDescr.patch
2023-02-21 16:44:45 +08:00

70 lines
2.3 KiB
Diff

From edb50ad66f7601ca9a3544a0e9045e8a8c60561f Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Mon, 7 Nov 2022 12:52:05 +0100
Subject: [PATCH] Bug 706057: Fix use-after-free in getOwnPropertyDescriptor.
getOwnPropertyDescriptor should create the descriptor object by
using [[DefineOwnProperty]], and not by looking through the prototype
chain where it may invoke getters and setters on the Object.prototype.
If there exists an Object.prototype.get property with a setter, that method is
invoked when it shouldn't. A malicious getter here can delete the property
currently being processed in getOwnPropertyDescriptor, and we'll end up
with a use-after-free bug.
Avoid this problem by following the spec and use js_defproperty rather than
js_setproperty to define own properties in getOwnPropertyDescriptor and
related functions.
---
jsobject.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/jsobject.c b/jsobject.c
index 78ea344..a58fc3a 100644
--- a/jsobject.c
+++ b/jsobject.c
@@ -134,25 +134,25 @@ static void O_getOwnPropertyDescriptor(js_State *J)
js_newobject(J);
if (!ref->getter && !ref->setter) {
js_pushvalue(J, ref->value);
- js_setproperty(J, -2, "value");
+ js_defproperty(J, -2, "value", 0);
js_pushboolean(J, !(ref->atts & JS_READONLY));
- js_setproperty(J, -2, "writable");
+ js_defproperty(J, -2, "writable", 0);
} else {
if (ref->getter)
js_pushobject(J, ref->getter);
else
js_pushundefined(J);
- js_setproperty(J, -2, "get");
+ js_defproperty(J, -2, "get", 0);
if (ref->setter)
js_pushobject(J, ref->setter);
else
js_pushundefined(J);
- js_setproperty(J, -2, "set");
+ js_defproperty(J, -2, "set", 0);
}
js_pushboolean(J, !(ref->atts & JS_DONTENUM));
- js_setproperty(J, -2, "enumerable");
+ js_defproperty(J, -2, "enumerable", 0);
js_pushboolean(J, !(ref->atts & JS_DONTCONF));
- js_setproperty(J, -2, "configurable");
+ js_defproperty(J, -2, "configurable", 0);
}
}
@@ -248,7 +248,7 @@ static void ToPropertyDescriptor(js_State *J, js_Object *obj, const char *name,
}
if (js_hasproperty(J, -1, "value")) {
hasvalue = 1;
- js_setproperty(J, -3, name);
+ js_defproperty(J, -3, name, 0);
}
if (!writable) atts |= JS_READONLY;
--
2.20.1