Listen on property_service_for_system socket for powerctl messages
It is easy to dos the property_service socket, since it will wait for a
complete data packet from one command before moving on to the next one.
To prevent low privilege apps interfering with system and root apps,
add a second property_service socket that only they can use.
However, since writes to properties are not thread-safe, limit use of
this second socket to just sys.powerctl messages. These are the messages
that this security issue is concerned about, and they do not actually
write to the properties, rather they are acted upon immediately.
Bug: 262208935
Test: Builds, boots
Ignore-AOSP-First: Security fix
Change-Id: I1e96444115de4cc0b021c6864922845de331f6a7
diff --git a/libc/include/sys/_system_properties.h b/libc/include/sys/_system_properties.h
index 943d4c6..1afb000 100644
--- a/libc/include/sys/_system_properties.h
+++ b/libc/include/sys/_system_properties.h
@@ -41,6 +41,7 @@
__BEGIN_DECLS
#define PROP_SERVICE_NAME "property_service"
+#define PROP_SERVICE_FOR_SYSTEM_NAME "property_service_for_system"
#define PROP_FILENAME "/dev/__properties__"
#define PROP_MSG_SETPROP 1