libproxy/libproxy-0.4.15-mozjs-use-after-free.patch
František Zatloukal a8f5153286 Build with mozjs68
2020-08-04 10:01:17 +02:00

39 lines
1.6 KiB
Diff

From 738785214546ec5bb772886019529b2a6519deaf Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@debian.org>
Date: Fri, 1 May 2020 19:04:22 +0100
Subject: [PATCH] mozjs: Avoid use-after-free
If we don't assign the temporary std::string returned by
url_.to_string() to a variable, then it immediately goes out of scope
and is freed, resulting in the result of c_str() pointing into freed
memory. This works about as well as you would expect.
Signed-off-by: Simon McVittie <smcv@debian.org>
---
libproxy/modules/pacrunner_mozjs.cpp | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/libproxy/modules/pacrunner_mozjs.cpp b/libproxy/modules/pacrunner_mozjs.cpp
index ade6d0a..aac6531 100644
--- a/libproxy/modules/pacrunner_mozjs.cpp
+++ b/libproxy/modules/pacrunner_mozjs.cpp
@@ -175,14 +175,11 @@ class mozjs_pacrunner : public pacrunner {
string run(const url& url_) throw (bad_alloc) {
// Build arguments to the FindProxyForURL() function
- const char *tmpurl = url_.to_string().c_str();
- const char *tmphost = url_.get_host().c_str();
- if (!tmpurl || !tmphost) {
- throw bad_alloc();
- }
+ string tmpurl(url_.to_string());
+ string tmphost(url_.get_host());
JS::AutoValueArray<2> args(this->jsctx);
- args[0].setString(JS_NewStringCopyZ(this->jsctx, tmpurl));
- args[1].setString(JS_NewStringCopyZ(this->jsctx, tmphost));
+ args[0].setString(JS_NewStringCopyZ(this->jsctx, tmpurl.c_str()));
+ args[1].setString(JS_NewStringCopyZ(this->jsctx, tmphost.c_str()));
// Find the proxy (call FindProxyForURL())
JS::RootedValue rval(this->jsctx);