diff --git a/compiler-rt/lib/asan/asan_poisoning.cpp b/compiler-rt/lib/asan/asan_poisoning.cpp
--- a/compiler-rt/lib/asan/asan_poisoning.cpp
+++ b/compiler-rt/lib/asan/asan_poisoning.cpp
@@ -444,17 +444,6 @@
   // uptr d2 = RoundUpTo(old_mid, granularity);
   // Currently we should be in this state:
   // [a, d1) is good, [d2, c) is bad, [d1, d2) is partially good.
-  // Make a quick sanity check that we are indeed in this state.
-  //
-  // FIXME: Two of these three checks are disabled until we fix
-  // https://github.com/google/sanitizers/issues/258.
-  // if (d1 != d2)
-  //  CHECK_EQ(*(u8*)MemToShadow(d1), old_mid - d1);
-  if (a + granularity <= d1)
-    CHECK_EQ(*(u8 *)MemToShadow(a), 0);
-  // if (d2 + granularity <= c && c <= end)
-  //   CHECK_EQ(*(u8 *)MemToShadow(c - granularity),
-  //            kAsanContiguousContainerOOBMagic);
 
   uptr b1 = RoundDownTo(new_end, granularity);
   uptr b2 = RoundUpTo(new_end, granularity);