electron/patches/chromium/support_mixed_sandbox_with_zygote.patch
2021-05-19 16:15:47 -07:00

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3.7 KiB
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jeremy Apthorp <nornagon@nornagon.net>
Date: Wed, 28 Nov 2018 13:20:27 -0800
Subject: support_mixed_sandbox_with_zygote.patch
On Linux, Chromium launches all new renderer processes via a "zygote"
process which has the sandbox pre-initialized (see
//docs/linux_zygote.md). In order to support mixed-sandbox mode, in
which some renderers are launched with the sandbox engaged and others
without it, we need the option to launch non-sandboxed renderers without
going through the zygote.
Chromium already supports a `--no-zygote` flag, but it turns off the
zygote completely, and thus also disables sandboxing. This patch allows
the `--no-zygote` flag to affect renderer processes on a case-by-case
basis, checking immediately prior to launch whether to go through the
zygote or not based on the command-line of the to-be-launched renderer.
This patch could conceivably be upstreamed, as it does not affect
production Chromium (which does not use the `--no-zygote` flag).
However, the patch would need to be reviewed by the security team, as it
does touch a security-sensitive class.
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index ec0f47781d42d55e907afd039e961a74ed9c7c9c..c54084b7b1b7b3459a4b34f4afc0891db5cdb6a7 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -392,10 +392,18 @@ class RendererSandboxedProcessLauncherDelegate
public:
RendererSandboxedProcessLauncherDelegate() = default;
+#if BUILDFLAG(USE_ZYGOTE_HANDLE)
+ RendererSandboxedProcessLauncherDelegate(bool use_zygote):
+ use_zygote_(use_zygote) {}
+#endif
+
~RendererSandboxedProcessLauncherDelegate() override = default;
#if BUILDFLAG(USE_ZYGOTE_HANDLE)
ZygoteHandle GetZygote() override {
+ if (!use_zygote_) {
+ return nullptr;
+ }
const base::CommandLine& browser_command_line =
*base::CommandLine::ForCurrentProcess();
base::CommandLine::StringType renderer_prefix =
@@ -413,6 +421,11 @@ class RendererSandboxedProcessLauncherDelegate
sandbox::policy::SandboxType GetSandboxType() override {
return sandbox::policy::SandboxType::kRenderer;
}
+
+ private:
+#if BUILDFLAG(USE_ZYGOTE_HANDLE)
+ bool use_zygote_ = true;
+#endif
};
#if defined(OS_WIN)
@@ -423,6 +436,9 @@ class RendererSandboxedProcessLauncherDelegateWin
RendererSandboxedProcessLauncherDelegateWin(base::CommandLine* cmd_line)
: renderer_code_integrity_enabled_(
GetContentClient()->browser()->IsRendererCodeIntegrityEnabled()) {
+#if BUILDFLAG(USE_ZYGOTE_HANDLE)
+ use_zygote_ = !cmd_line->HasSwitch(switches::kNoZygote);
+#endif
if (cmd_line->HasSwitch(switches::kJavaScriptFlags)) {
std::string js_flags =
cmd_line->GetSwitchValueASCII(switches::kJavaScriptFlags);
@@ -1887,9 +1903,15 @@ bool RenderProcessHostImpl::Init() {
std::unique_ptr<SandboxedProcessLauncherDelegate> sandbox_delegate =
std::make_unique<RendererSandboxedProcessLauncherDelegateWin>(
cmd_line.get());
+#else
+#if BUILDFLAG(USE_ZYGOTE_HANDLE)
+ bool use_zygote = !cmd_line->HasSwitch(switches::kNoZygote);
+ std::unique_ptr<SandboxedProcessLauncherDelegate> sandbox_delegate =
+ std::make_unique<RendererSandboxedProcessLauncherDelegate>(use_zygote);
#else
std::unique_ptr<SandboxedProcessLauncherDelegate> sandbox_delegate =
std::make_unique<RendererSandboxedProcessLauncherDelegate>();
+#endif
#endif
// Spawn the child process asynchronously to avoid blocking the UI thread.
// As long as there's no renderer prefix, we can use the zygote process