The earliest build that failed is https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20MSan%20Tests/11668

But no clear culprit.

All failures are similar:

[ RUN      ] GLImageNativePixmap/GLImageNativePixmapToDmabufTest/3.GLTexture2DToDmabuf
Uninitialized bytes in __interceptor_strlen at offset 24 inside [0x7ffe0af33d60, 45)
==32174==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f8ff3777212 in _eglLinkScreen ??:?
    #1 0x7f8ff3777212 in ?? ??:0
    #2 0x7f8ff3774b96 in _eglReleaseDisplayResources ??:?
    #3 0x7f8ff3774b96 in ?? ??:0
    #4 0x7f8ff3774cd5 in _eglReleaseDisplayResources ??:?
    #5 0x7f8ff3774cd5 in ?? ??:0
    #6 0x7f8ff3774f03 in _eglReleaseDisplayResources ??:?
    #7 0x7f8ff3774f03 in ?? ??:0
    #8 0x7f8ff3775183 in _eglReleaseDisplayResources ??:?
    #9 0x7f8ff3775183 in ?? ??:0
    #10 0x7f8ff37752ec in _eglReleaseDisplayResources ??:?
    #11 0x7f8ff37752ec in ?? ??:0
    #12 0x7f8ff3771f47 in eglGetProcAddress ??:0:0
    #13 0x157d0ab in operator()<const char *&> ./../../base/memory/protected_memory_cfi.h:43:12
    #14 0x157d0ab in gl::GetGLProcAddress(char const*) ./../../ui/gl/gl_implementation.cc:183:0
    #15 0x15a3307 in gl::DriverEGL::InitializeStaticBindings() ./../../ui/gl/gl_bindings_autogen_egl.cc:62:11
    #16 0x15afeab in gl::InitializeStaticGLBindingsEGL() ./../../ui/gl/gl_egl_api_implementation.cc:20:16
    #17 0x22211ae in InitializeStaticEGLInternal ./../../ui/gl/init/gl_initializer_x11.cc:136:3
    #18 0x22211ae in gl::init::InitializeStaticGLBindings(gl::GLImplementation) ./../../ui/gl/init/gl_initializer_x11.cc:180:0
    #19 0x220da64 in gl::init::InitializeGLOneOffImplementation(gl::GLImplementation, bool, bool, bool, bool) ./../../ui/gl/init/gl_factory.cc:97:7
    #20 0x1f993c3 in gl::GLSurfaceTestSupport::InitializeOneOffImplementation(gl::GLImplementation, bool) ./../../ui/gl/test/gl_surface_test_support.cc:106:3
    #21 0x1f8ee0f in gl::GLImageTestSupport::InitializeGL(base::Optional<gl::GLImplementation>) ./../../ui/gl/test/gl_image_test_support.cc:39:3
    #22 0x5f5ed7 in gl::GLImageTest<gl::(anonymous namespace)::GLImageNativePixmapTestDelegate<(gfx::BufferFormat)15> >::SetUp() ./../../ui/gl/test/gl_image_test_template.h:57:5
    #23 0x13149d5 in HandleExceptionsInMethodIfSupported<testing::Test, void> ./../../third_party/googletest/src/googletest/src/gtest.cc:0:0
    #24 0x13149d5 in testing::Test::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:2518:0
    #25 0x13178a7 in testing::TestInfo::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:2698:11
    #26 0x1319399 in testing::TestCase::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:2816:28
    #27 0x1352f54 in testing::internal::UnitTestImpl::RunAllTests() ./../../third_party/googletest/src/googletest/src/gtest.cc:5182:43
    #28 0x1351827 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> ./../../third_party/googletest/src/googletest/src/gtest.cc:0:0
    #29 0x1351827 in testing::UnitTest::Run() ./../../third_party/googletest/src/googletest/src/gtest.cc:4791:0
    #30 0x30cca30 in RUN_ALL_TESTS ./../../third_party/googletest/src/googletest/include/gtest/gtest.h:2333:46
    #31 0x30cca30 in base::TestSuite::Run() ./../../base/test/test_suite.cc:295:0
    #32 0x3134905 in Run ./../../base/callback.h:99:12
    #33 0x3134905 in base::(anonymous namespace)::LaunchUnitTestsInternal(base::OnceCallback<int ()>, unsigned long, int, bool, base::OnceCallback<void ()>) ./../../base/test/launcher/unit_test_launcher.cc:225:0
    #34 0x31340c7 in base::LaunchUnitTests(int, char**, base::OnceCallback<int ()>) ./../../base/test/launcher/unit_test_launcher.cc:576:10
    #35 0x621215 in main ./../../ui/gl/test/run_all_unittests.cc:117:10
    #36 0x7f8ff8c9cf44 in __libc_start_main ??:0:0
    #37 0x4c5029 in _start ??:0:0
  Uninitialized value was created by an allocation of 'dir_static' in the stack frame of function 'FcCacheTimeValid'
    #0 0x2e49cf0 in FcCacheTimeValid ./../../third_party/fontconfig/src/src/fccache.c:803:0
SUMMARY: MemorySanitizer: use-of-uninitialized-value (/usr/lib/x86_64-linux-gnu/mesa-egl/libEGL.so.1+0xf212)
Exiting

I don't see an obvious culprit in the blamelist for that build. :-(

+kbr: Could you help route this?

The failing tests are:

GLImageNativePixmap/GLImageTest/3.Create
GLImageNativePixmap/GLImageNativePixmapToDmabufTest/1.GLTexture2DToDmabuf
GLImageNativePixmap/GLImageNativePixmapToDmabufTest/0.GLTexture2DToDmabuf
GLImageNativePixmap/GLImageTest/2.Create
GLSurfaceEGLTest.SurfaceFormatTest
GLImageNativePixmap/GLImageOddSizeTest/2.Create
GLImageNativePixmap/GLImageTest/1.Create
GLImageNativePixmap/GLImageTest/0.Create
GLImageNativePixmap/GLImageOddSizeTest/0.Create
GLImageNativePixmap/GLImageNativePixmapToDmabufTest/3.GLTexture2DToDmabuf
GLImageNativePixmap/GLImageNativePixmapToDmabufTest/2.GLTexture2DToDmabuf
GLImageNativePixmap/GLImageOddSizeTest/1.Create
GLImageNativePixmap/GLImageOddSizeTest/3.Create

It looks like some of the Ubuntu bots have a libGLESv2.so and libEGL.so, and therefore try to run the test (and crash), and some don't, so they skip the test.

Failing run:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20MSan%20Tests/11669
https://chromium-swarm.appspot.com/task?id=400bb0e97728e310&refresh=10&show_raw=1

which ran on this bot:
https://chromium-swarm.appspot.com/bot?id=gce-trusty-canary-e973df7c-us-central1-c-xk0k&sort_stats=total%3Adesc

where this passing run:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20MSan%20Tests/11670
https://chromium-swarm.appspot.com/task?id=400be63bfdc88b10&refresh=10&show_raw=1

ran on this bot:
https://chromium-swarm.appspot.com/bot?id=gce-trusty-02248837-us-west1-c-70z6&sort_stats=total%3Adesc

and reported:
[ RUN      ] GLImageNativePixmap/GLImageNativePixmapToDmabufTest/0.GLTexture2DToDmabuf
[25089:25089:0919/112559.682763:14797875789:ERROR:gl_implementation.cc(281)] Failed to load libGLESv2.so.2: libGLESv2.so.2: cannot open shared object file: No such file or directory
[25089:25089:0919/112559.729174:14797922195:WARNING:gl_image_native_pixmap_unittest.cc(29)] Skip test, missing extension EGL_MESA_image_dma_buf_export

We should skip these tests with the memory sanitizer turned on.

gklassen@: as pixel wrangler this week could you please #ifdef out these tests when the memory sanitizer is in use? For this you can use:

#if !defined(MEMORY_SANITIZER)
// Fails under MSAN:  crbug.com/886995 
...Test code...
#endif

or similar.

Thanks.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cde6bdf69d88964dafb6bdc7b8236356c91ebea6

commit cde6bdf69d88964dafb6bdc7b8236356c91ebea6
Author: Weiliang Chen <weiliangc@chromium.org>
Date: Thu Sep 20 16:37:41 2018

Skip GL unit tests that are failing for MSAN

Skip GLImageNativePixmap tests and GLSurfaceEGLTest.SurfaceFormatTest
for MSAN.

TBR=kbr

Bug:  886995 
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I1b29243bd8219e81187aa0e8c5d8f50371423126
Reviewed-on: https://chromium-review.googlesource.com/1236833
Commit-Queue: weiliangc <weiliangc@chromium.org>
Reviewed-by: weiliangc <weiliangc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592831}
[modify] https://crrev.com/cde6bdf69d88964dafb6bdc7b8236356c91ebea6/ui/gl/gl_image_native_pixmap_unittest.cc
[modify] https://crrev.com/cde6bdf69d88964dafb6bdc7b8236356c91ebea6/ui/gl/gl_surface_egl_unittest.cc

Thank you Wei for picking this up! Please reopen or file a new bug if failures persist.