// Copyright 2018 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include <string.h> #include <sys/mman.h> #include <algorithm> #include "gtest/gtest.h" #include "test/util/fs_util.h" #include "test/util/posix_error.h" #include "test/util/proc_util.h" #include "test/util/test_util.h" namespace gvisor { namespace testing { namespace { // Ensure that the vvar page cannot be made writable. TEST(VvarTest, WriteVvar) { auto contents = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/self/maps")); auto maps = ASSERT_NO_ERRNO_AND_VALUE(ParseProcMaps(contents)); auto it = std::find_if(maps.begin(), maps.end(), [](const ProcMapsEntry& e) { return e.filename == "[vvar]"; }); SKIP_IF(it == maps.end()); EXPECT_THAT(mprotect(reinterpret_cast<void*>(it->start), kPageSize, PROT_READ | PROT_WRITE), SyscallFailsWithErrno(EACCES)); } } // namespace } // namespace testing } // namespace gvisor