From 00aa39e85336e2f2dc8799dea7d9f3057d38ef67 Mon Sep 17 00:00:00 2001
From: Gian-Carlo Pascutto <gcp@mozilla.com>
Date: Wed, 30 Oct 2019 17:59:15 +0000
Subject: [PATCH] Bug 1533918 - Disallow CrossProcessMutex when sandboxing is
 enabled. r=botond

Differential Revision: https://phabricator.services.mozilla.com/D50941

--HG--
extra : moz-landing-system : lando
---
 ipc/glue/CrossProcessMutex_posix.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ipc/glue/CrossProcessMutex_posix.cpp b/ipc/glue/CrossProcessMutex_posix.cpp
index 3320a0076c69..f7f5c69536b9 100644
--- a/ipc/glue/CrossProcessMutex_posix.cpp
+++ b/ipc/glue/CrossProcessMutex_posix.cpp
@@ -38,6 +38,11 @@ static void InitMutex(pthread_mutex_t* mMutex) {
 
 CrossProcessMutex::CrossProcessMutex(const char*)
     : mMutex(nullptr), mCount(nullptr) {
+#if defined(MOZ_SANDBOX)
+  // POSIX mutexes in shared memory aren't guaranteed to be safe - and
+  // they specifically are not on Linux.
+  MOZ_RELEASE_ASSERT(false);
+#endif
   mSharedBuffer = new ipc::SharedMemoryBasic;
   if (!mSharedBuffer->Create(sizeof(MutexData))) {
     MOZ_CRASH();