CgroupV1Controller does not crash in the current OpenJDK code but it is easy to write code which does crash.

CgroupV2Controller constructor just leaks memory.

[ RUN ] cgroupTest.cgroupv1_ctor_shallow
=================================================================
==621011==ERROR: AddressSanitizer: heap-use-after-free on address 0x50400000ddd8 at pc 0x7fd104f6901d bp 0x7fff0b16d630 sp 0x7fff0b16d628
READ of size 8 at 0x50400000ddd8 thread T0
    #0 0x7fd104f6901c in CgroupV1Controller::set_subsystem_path(char*) openjdk-git/src/hotspot/os/linux/cgroupV1Subsystem_linux.cpp:43
    #1 0x7fd1090dba34 in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) googletest-git/googletest/src/gtest.cc:2671
    #2 0x7fd1090dba34 in testing::Test::Run() googletest-git/googletest/src/gtest.cc:2688
    #3 0x7fd1090dba34 in testing::Test::Run() googletest-git/googletest/src/gtest.cc:2678
    #4 0x7fd1090dc1c4 in testing::TestInfo::Run() googletest-git/googletest/src/gtest.cc:2837
    #5 0x7fd1091018ce in testing::TestSuite::Run() googletest-git/googletest/src/gtest.cc:3016
    #6 0x7fd1091018ce in testing::TestSuite::Run() googletest-git/googletest/src/gtest.cc:2969
    #7 0x7fd10911597e in testing::internal::UnitTestImpl::RunAllTests() googletest-git/googletest/src/gtest.cc:5922
    #8 0x7fd1091166e7 in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) googletest-git/googletest/src/gtest.cc:2671
    #9 0x7fd1091166e7 in testing::UnitTest::Run() googletest-git/googletest/src/gtest.cc:5486
    #10 0x7fd102dc3ce4 in RUN_ALL_TESTS() googletest-git/googletest/include/gtest/gtest.h:2317
    #11 0x7fd102dc3ce4 in runUnitTestsInner openjdk-git/test/hotspot/gtest/gtestMain.cpp:290
    #12 0x7fd102dc4489 in runUnitTests openjdk-git/test/hotspot/gtest/gtestMain.cpp:371
    #13 0x564b5ea1a1e3 in main openjdk-git/test/hotspot/gtest/gtestLauncher.cpp:40
    #14 0x7fd101a39087 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #15 0x7fd101a3914a in __libc_start_main_impl ../csu/libc-start.c:360
    #16 0x564b5ea1a0b4 in _start (openjdk-git/build/linux-x86_64-server-fastdebug/images/test/hotspot/gtest/server/gtestLauncher+0x10b4) (BuildId: 969a8b34c6a6b698d2ac61361d12ec005cc359a8)

0x50400000ddd8 is located 8 bytes inside of 40-byte region [0x50400000ddd0,0x50400000ddf8)
freed by thread T0 here:
    #0 0x7fd10b8f6638 in free.part.0 (/lib64/libasan.so.8+0xf6638) (BuildId: 79824421bd82bb3ef4addf048e1265e2a93cfc64)
    #1 0x7fd1076dfd5a in raw_free openjdk-git/src/hotspot/share/nmt/nmtPreInit.cpp:38
    #2 0x7fd1076dfd5a in NMTPreInitAllocation::do_free(NMTPreInitAllocation*) openjdk-git/src/hotspot/share/nmt/nmtPreInit.cpp:86
    #3 0x7fd10786135c in NMTPreInit::handle_free(void*) openjdk-git/src/hotspot/share/nmt/nmtPreInit.hpp:348
    #4 0x7fd10786135c in os::free(void*) openjdk-git/src/hotspot/share/runtime/os.cpp:775
    #5 0x7fd10304da47 in CHeapObjBase::operator delete(void*) openjdk-git/src/hotspot/share/memory/allocation.hpp:172
    #6 0x7fd10304da47 in CHeapObj<(MEMFLAGS)9>::operator delete(void*) openjdk-git/src/hotspot/share/memory/allocation.hpp:217
    #7 0x7fd10304da47 in cgroupTest_cgroupv1_ctor_shallow_Test::TestBody() openjdk-git/test/hotspot/gtest/runtime/test_cgroupSubsystem_linux.cpp:484
    #8 0x7fd1090dba34 in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) googletest-git/googletest/src/gtest.cc:2671
    #9 0x7fd1090dba34 in testing::Test::Run() googletest-git/googletest/src/gtest.cc:2688
    #10 0x7fd1090dba34 in testing::Test::Run() googletest-git/googletest/src/gtest.cc:2678
    #11 0x7fd1090dc1c4 in testing::TestInfo::Run() googletest-git/googletest/src/gtest.cc:2837
    #12 0x7fd1091018ce in testing::TestSuite::Run() googletest-git/googletest/src/gtest.cc:3016
    #13 0x7fd1091018ce in testing::TestSuite::Run() googletest-git/googletest/src/gtest.cc:2969
    #14 0x7fd10911597e in testing::internal::UnitTestImpl::RunAllTests() googletest-git/googletest/src/gtest.cc:5922
    #15 0x7fd1091166e7 in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) googletest-git/googletest/src/gtest.cc:2671
    #16 0x7fd1091166e7 in testing::UnitTest::Run() googletest-git/googletest/src/gtest.cc:5486
    #17 0x7fd102dc3ce4 in RUN_ALL_TESTS() googletest-git/googletest/include/gtest/gtest.h:2317
    #18 0x7fd102dc3ce4 in runUnitTestsInner openjdk-git/test/hotspot/gtest/gtestMain.cpp:290
    #19 0x7fd102dc4489 in runUnitTests openjdk-git/test/hotspot/gtest/gtestMain.cpp:371
    #20 0x564b5ea1a1e3 in main openjdk-git/test/hotspot/gtest/gtestLauncher.cpp:40
    #21 0x7fd101a39087 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #22 0x7fd101a3914a in __libc_start_main_impl ../csu/libc-start.c:360
    #23 0x564b5ea1a0b4 in _start (openjdk-git/build/linux-x86_64-server-fastdebug/images/test/hotspot/gtest/server/gtestLauncher+0x10b4) (BuildId: 969a8b34c6a6b698d2ac61361d12ec005cc359a8)

previously allocated by thread T0 here:
    #0 0x7fd10b8f7997 in malloc (/lib64/libasan.so.8+0xf7997) (BuildId: 79824421bd82bb3ef4addf048e1265e2a93cfc64)
    #1 0x7fd1076dfa3e in raw_malloc openjdk-git/src/hotspot/share/nmt/nmtPreInit.cpp:36
    #2 0x7fd1076dfa3e in raw_checked_malloc openjdk-git/src/hotspot/share/nmt/nmtPreInit.cpp:45
    #3 0x7fd1076dfa3e in NMTPreInitAllocation::do_alloc(unsigned long) openjdk-git/src/hotspot/share/nmt/nmtPreInit.cpp:71
    #4 0x7fd107861d57 in NMTPreInit::handle_malloc(void**, unsigned long) openjdk-git/src/hotspot/share/nmt/nmtPreInit.hpp:274
    #5 0x7fd107861d57 in os::malloc(unsigned long, MEMFLAGS, NativeCallStack const&) openjdk-git/src/hotspot/share/runtime/os.cpp:640
    #6 0x7fd1044dac03 in AllocateHeap(unsigned long, MEMFLAGS, NativeCallStack const&, AllocFailStrategy::AllocFailEnum) openjdk-git/src/hotspot/share/memory/allocation.cpp:42
    #7 0x7fd1044dac03 in AllocateHeap(unsigned long, MEMFLAGS, AllocFailStrategy::AllocFailEnum) openjdk-git/src/hotspot/share/memory/allocation.cpp:52
    #8 0x7fd10304d871 in CHeapObjBase::operator new(unsigned long, MEMFLAGS) openjdk-git/src/hotspot/share/memory/allocation.hpp:127
    #9 0x7fd10304d871 in CHeapObj<(MEMFLAGS)9>::operator new(unsigned long) openjdk-git/src/hotspot/share/memory/allocation.hpp:181
    #10 0x7fd10304d871 in cgroupTest_cgroupv1_ctor_shallow_Test::TestBody() openjdk-git/test/hotspot/gtest/runtime/test_cgroupSubsystem_linux.cpp:482
    #11 0x7fd1090dba34 in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) googletest-git/googletest/src/gtest.cc:2671
    #12 0x7fd1090dba34 in testing::Test::Run() googletest-git/googletest/src/gtest.cc:2688
    #13 0x7fd1090dba34 in testing::Test::Run() googletest-git/googletest/src/gtest.cc:2678
    #14 0x7fd1090dc1c4 in testing::TestInfo::Run() googletest-git/googletest/src/gtest.cc:2837
    #15 0x7fd1091018ce in testing::TestSuite::Run() googletest-git/googletest/src/gtest.cc:3016
    #16 0x7fd1091018ce in testing::TestSuite::Run() googletest-git/googletest/src/gtest.cc:2969
    #17 0x7fd10911597e in testing::internal::UnitTestImpl::RunAllTests() googletest-git/googletest/src/gtest.cc:5922
    #18 0x7fd1091166e7 in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) googletest-git/googletest/src/gtest.cc:2671
    #19 0x7fd1091166e7 in testing::UnitTest::Run() googletest-git/googletest/src/gtest.cc:5486
    #20 0x7fd102dc3ce4 in RUN_ALL_TESTS() googletest-git/googletest/include/gtest/gtest.h:2317
    #21 0x7fd102dc3ce4 in runUnitTestsInner openjdk-git/test/hotspot/gtest/gtestMain.cpp:290
    #22 0x7fd102dc4489 in runUnitTests openjdk-git/test/hotspot/gtest/gtestMain.cpp:371
    #23 0x564b5ea1a1e3 in main openjdk-git/test/hotspot/gtest/gtestLauncher.cpp:40
    #24 0x7fd101a39087 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #25 0x7fd101a3914a in __libc_start_main_impl ../csu/libc-start.c:360
    #26 0x564b5ea1a0b4 in _start (openjdk-git/build/linux-x86_64-server-fastdebug/images/test/hotspot/gtest/server/gtestLauncher+0x10b4) (BuildId: 969a8b34c6a6b698d2ac61361d12ec005cc359a8)

SUMMARY: AddressSanitizer: heap-use-after-free openjdk-git/src/hotspot/os/linux/cgroupV1Subsystem_linux.cpp:43 in CgroupV1Controller::set_subsystem_path(char*)
Shadow bytes around the buggy address:
  0x50400000db00: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fd
  0x50400000db80: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fa
  0x50400000dc00: fa fa fd fd fd fd fd fa fa fa fd fd fd fd fd fd
  0x50400000dc80: fa fa 00 00 00 00 00 fa fa fa 00 00 00 00 00 fa
  0x50400000dd00: fa fa 00 00 00 00 00 06 fa fa 00 00 00 00 00 fa
=>0x50400000dd80: fa fa 00 00 00 00 00 fa fa fa fd[fd]fd fd fd fa
  0x50400000de00: fa fa 00 00 00 00 00 fa fa fa fa fa fa fa fa fa
  0x50400000de80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x50400000df00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x50400000df80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x50400000e000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable: 00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone: fa
  Freed heap region: fd
  Stack left redzone: f1
  Stack mid redzone: f2
  Stack right redzone: f3
  Stack after return: f5
  Stack use after scope: f8
  Global redzone: f9
  Global init order: f6
  Poisoned by user: f7
  Container overflow: fc
  Array cookie: ac
  Intra object redzone: bb
  ASan internal: fe
  Left alloca redzone: ca
  Right alloca redzone: cb
==621011==ABORTING