Mount /data with MS_NOEXEC
We want to ensure that W^X is guaranteed for Microdroid VMs. This change
doesn't guarantee that W^X is enforced for FULL_DEBUG VMs, as a user can
enable adb root, and remount the /data without MS_NOEXEC flag.
This is intended, as it allows developers to debug & get familiar with
the Microdroid execution environment.
This is an attempt at relanding aosp/I622e3d95d9d8fd6d26bfb690499acf7208ca4d52
Bug: 265261525
Test: atest MicrodroidTestApp
Change-Id: Id826bd46f6fcf2ed1cf64710cfa057ffe7036ef8
diff --git a/tests/testapk/src/native/testbinary.cpp b/tests/testapk/src/native/testbinary.cpp
index 07c8cd4..285dae9 100644
--- a/tests/testapk/src/native/testbinary.cpp
+++ b/tests/testapk/src/native/testbinary.cpp
@@ -21,6 +21,7 @@
#include <android-base/scopeguard.h>
#include <android/log.h>
#include <fcntl.h>
+#include <fstab/fstab.h>
#include <fsverity_digests.pb.h>
#include <linux/vm_sockets.h>
#include <stdint.h>
@@ -40,6 +41,10 @@
using android::base::make_scope_guard;
using android::base::Result;
using android::base::unique_fd;
+using android::fs_mgr::Fstab;
+using android::fs_mgr::FstabEntry;
+using android::fs_mgr::GetEntryForMountPoint;
+using android::fs_mgr::ReadFstabFromFile;
using aidl::com::android::microdroid::testservice::BnTestService;
using ndk::ScopedAStatus;
@@ -263,6 +268,22 @@
return ScopedAStatus::ok();
}
+ ScopedAStatus getMountFlags(const std::string& mount_point, int32_t* out) override {
+ Fstab fstab;
+ if (!ReadFstabFromFile("/proc/mounts", &fstab)) {
+ return ScopedAStatus::fromExceptionCodeWithMessage(EX_SERVICE_SPECIFIC,
+ "Failed to read /proc/mounts");
+ }
+ FstabEntry* entry = GetEntryForMountPoint(&fstab, mount_point);
+ if (entry == nullptr) {
+ std::string msg = mount_point + " not found in /proc/mounts";
+ return ScopedAStatus::fromExceptionCodeWithMessage(EX_SERVICE_SPECIFIC,
+ msg.c_str());
+ }
+ *out = entry->flags;
+ return ScopedAStatus::ok();
+ }
+
ScopedAStatus quit() override { exit(0); }
};
auto testService = ndk::SharedRefBase::make<TestService>();