diff --git a/compiler-rt/lib/lsan/CMakeLists.txt b/compiler-rt/lib/lsan/CMakeLists.txt
--- a/compiler-rt/lib/lsan/CMakeLists.txt
+++ b/compiler-rt/lib/lsan/CMakeLists.txt
@@ -3,6 +3,24 @@
 set(LSAN_CFLAGS ${SANITIZER_COMMON_CFLAGS})
 append_rtti_flag(OFF LSAN_CFLAGS)
 
+# When lsan scans the stack for detecting reachable pointers, it's possible for
+# a leaked pointer, which was pushed to the stack on an earlier function call,
+# to still exist on the stack when doing a leak check if that part of the stack
+# was not overwritten. In particular, if there's any uninitialized data in the
+# lsan runtime, and the SP we start from is sufficiently deep into the runtime,
+# then a leaked pointer could be marked as reachable. Such instances could be
+# mitigated by clobbering any uninitialized data. Note that this won't cover
+# all possible uninitialized stack contents, such as those used for register
+# spill slots, unused portions for alignment, or even local variables not
+# yet in scope at a certain point in the function.
+if(LSAN_AUTO_VAR_INIT_PATTERN)
+  list(APPEND LSAN_CFLAGS -ftrivial-auto-var-init=pattern)
+elseif(LSAN_AUTO_VAR_INIT_ZERO)
+  # Note this may hide some bugs in the lsan runtime itself that would involve
+  # reading uninitialized memory.
+  list(APPEND LSAN_CFLAGS -ftrivial-auto-var-init=zero)
+endif()
+
 # Too many existing bugs, needs cleanup.
 append_list_if(COMPILER_RT_HAS_WNO_FORMAT -Wno-format LSAN_CFLAGS)