diff --git a/clang/docs/AddressSanitizer.rst b/clang/docs/AddressSanitizer.rst
--- a/clang/docs/AddressSanitizer.rst
+++ b/clang/docs/AddressSanitizer.rst
@@ -14,8 +14,9 @@
 
 * Out-of-bounds accesses to heap, stack and globals
 * Use-after-free
-* Use-after-return (runtime flag `ASAN_OPTIONS=detect_stack_use_after_return=1`)
-* Use-after-scope (clang flag `-fsanitize-address-use-after-scope`)
+* Use-after-return (clang flag ``-fsanitize-address-use-after-return=(never|runtime|always)`` default: ``runtime``)
+    * Enable ``runtime`` with: ``ASAN_OPTIONS=detect_stack_use_after_return=1``
+* Use-after-scope (clang flag ``-fsanitize-address-use-after-scope``)
 * Double-free, invalid free
 * Memory leaks (experimental)
 
diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -881,6 +881,15 @@
 * ``global`` - Emit module destructors that are called via a platform specific array (see `llvm.global_dtors`).
 * ``none`` - Do not emit module destructors.
 
+.. option:: -fsanitize-address-use-after-return=<mode>
+
+Select the enabling method of detecting stack use-after-return in AddressSanitizer.
+
+Valid options are:
+* ``never`` - Do not detect use-after-return.
+* ``runtime`` - Detect use-after-return with runtime ON/OFF switch (environment variable `ASAN_OPTIONS=detect_stack_use_after_return=1`, default: 0)
+* ``always`` - Detect use-after-return.
+
 .. option:: -fsanitize-ignorelist=<arg>
 
 Path to ignorelist file for sanitizers
diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
--- a/clang/docs/UsersManual.rst
+++ b/clang/docs/UsersManual.rst
@@ -1848,6 +1848,16 @@
   link-time optimizations like whole program inter-procedural basic block
   reordering.
 
+.. option:: -fsanitize-address-use-after-return=<mode>
+
+  When paired with ``-fsanitize=address``, this changes how detection of stack use-after-return (UAR) behaves.
+
+  * ``never``: Completely disables detection of UAR errors (reduces code size).
+  * ``runtime``: Adds the code for detection, but must be enabled via the runtime environment (``ASAN_OPTIONS=detect_stack_use_after_return=1``).
+  * ``always``: Enables detection of UAR errors in all cases. (reduces code size, but not as much as ``never``).
+
+  The default is ``-fsanitize-address-use-after-return=runtime``.
+
 Profile Guided Optimization
 ---------------------------
 
@@ -3724,6 +3734,8 @@
                               Enable linker dead stripping of globals in AddressSanitizer
       -fsanitize-address-poison-custom-array-cookie
                               Enable poisoning array cookies when using custom operator new[] in AddressSanitizer
+      -fsanitize-address-use-after-return=<mode>
+                              Select the mode of detecting stack use-after-return in AddressSanitizer
       -fsanitize-address-use-after-scope
                               Enable use-after-scope detection in AddressSanitizer
       -fsanitize-address-use-odr-indicator