Index: lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -9133,6 +9133,161 @@
 #define INIT_PCLOSE
 #endif
 
+#if SANITIZER_INTERCEPT_FUNOPEN
+typedef int (*funopen_readfn)(void *cookie, char *buf, int len);
+typedef int (*funopen_writefn)(void *cookie, const char *buf, int len);
+typedef OFF_T (*funopen_seekfn)(void *cookie, OFF_T offset, int whence);
+typedef int (*funopen_closefn)(void *cookie);
+
+struct WrappedCookie {
+  void *real_cookie;
+  funopen_readfn real_read;
+  funopen_writefn real_write;
+  funopen_seekfn real_seek;
+  funopen_closefn real_close;
+};
+
+static int wrapped_read(void *cookie, char *buf, int len) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
+  WrappedCookie *wrapped_cookie = (WrappedCookie *)cookie;
+  funopen_readfn real_read = wrapped_cookie->real_read;
+  return real_read(wrapped_cookie->real_cookie, buf, len);
+}
+
+static int wrapped_write(void *cookie, const char *buf, int len) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
+  WrappedCookie *wrapped_cookie = (WrappedCookie *)cookie;
+  funopen_writefn real_write = wrapped_cookie->real_write;
+  return real_write(wrapped_cookie->real_cookie, buf, len);
+}
+
+static OFF_T wrapped_seek(void *cookie, OFF_T offset, int whence) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
+  WrappedCookie *wrapped_cookie = (WrappedCookie *)cookie;
+  funopen_seekfn real_seek = wrapped_cookie->real_seek;
+  return real_seek(wrapped_cookie->real_cookie, offset, whence);
+}
+
+static int wrapped_close(void *cookie) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(1);
+  WrappedCookie *wrapped_cookie = (WrappedCookie *)cookie;
+  funopen_closefn real_close = wrapped_cookie->real_close;
+  int res = real_close(wrapped_cookie->real_cookie);
+  InternalFree(wrapped_cookie);
+  return res;
+}
+
+INTERCEPTOR(__sanitizer_FILE *, funopen, void *cookie, funopen_readfn readfn,
+            funopen_writefn writefn, funopen_seekfn seekfn,
+            funopen_closefn closefn) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, funopen, cookie, readfn, writefn,
+                           seekfn, closefn);
+
+  WrappedCookie *wrapped_cookie =
+      (WrappedCookie *)InternalAlloc(sizeof(WrappedCookie));
+  wrapped_cookie->real_cookie = cookie;
+  wrapped_cookie->real_read = readfn;
+  wrapped_cookie->real_write = writefn;
+  wrapped_cookie->real_seek = seekfn;
+  wrapped_cookie->real_close = closefn;
+
+  __sanitizer_FILE *res = REAL(funopen)(wrapped_cookie,
+                                        readfn  ? wrapped_read  : nullptr,
+                                        writefn ? wrapped_write : nullptr,
+                                        seekfn  ? wrapped_seek  : nullptr,
+                                        closefn ? wrapped_close : nullptr);
+  if (res) unpoison_file(res);
+  return res;
+}
+#define INIT_FUNOPEN COMMON_INTERCEPT_FUNCTION(funopen)
+#else
+#define INIT_FUNOPEN
+#endif
+
+#if SANITIZER_INTERCEPT_FUNOPEN2
+typedef SSIZE_T (*funopen2_readfn)(void *cookie, void *buf, SIZE_T len);
+typedef SSIZE_T (*funopen2_writefn)(void *cookie, const void *buf, SIZE_T len);
+typedef OFF_T (*funopen2_seekfn)(void *cookie, OFF_T offset, int whence);
+typedef int (*funopen2_flushfn)(void *cookie);
+typedef int (*funopen2_closefn)(void *cookie);
+
+struct WrappedCookie2 {
+  void *real_cookie;
+  funopen2_readfn real_read;
+  funopen2_writefn real_write;
+  funopen2_seekfn real_seek;
+  funopen2_flushfn real_flush;
+  funopen2_closefn real_close;
+};
+
+static SSIZE_T wrapped_read2(void *cookie, void *buf, SIZE_T len) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
+  WrappedCookie2 *wrapped_cookie = (WrappedCookie2 *)cookie;
+  funopen2_readfn real_read = wrapped_cookie->real_read;
+  return real_read(wrapped_cookie->real_cookie, buf, len);
+}
+
+static SSIZE_T wrapped_write2(void *cookie, const void *buf, SIZE_T len) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
+  WrappedCookie2 *wrapped_cookie = (WrappedCookie2 *)cookie;
+  funopen2_writefn real_write = wrapped_cookie->real_write;
+  return real_write(wrapped_cookie->real_cookie, buf, len);
+}
+
+static OFF_T wrapped_seek2(void *cookie, OFF_T offset, int whence) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(3);
+  WrappedCookie2 *wrapped_cookie = (WrappedCookie2 *)cookie;
+  funopen2_seekfn real_seek = wrapped_cookie->real_seek;
+  return real_seek(wrapped_cookie->real_cookie, offset, whence);
+}
+
+static int wrapped_flush2(void *cookie) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(1);
+  WrappedCookie2 *wrapped_cookie = (WrappedCookie2 *)cookie;
+  funopen2_flushfn real_flush = wrapped_cookie->real_flush;
+  return real_flush(wrapped_cookie->real_cookie);
+}
+
+static int wrapped_close2(void *cookie) {
+  COMMON_INTERCEPTOR_UNPOISON_PARAM(1);
+  WrappedCookie2 *wrapped_cookie = (WrappedCookie2 *)cookie;
+  funopen2_closefn real_close = wrapped_cookie->real_close;
+  int res = real_close(wrapped_cookie->real_cookie);
+  InternalFree(wrapped_cookie);
+  return res;
+}
+
+INTERCEPTOR(__sanitizer_FILE *, funopen2, void *cookie, funopen2_readfn readfn,
+            funopen2_writefn writefn, funopen2_seekfn seekfn,
+            funopen2_flushfn flushfn, funopen2_closefn closefn) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, funopen2, cookie, readfn, writefn,
+                           seekfn, flushfn, closefn);
+
+  WrappedCookie2 *wrapped_cookie =
+      (WrappedCookie2 *)InternalAlloc(sizeof(WrappedCookie2));
+  wrapped_cookie->real_cookie = cookie;
+  wrapped_cookie->real_read = readfn;
+  wrapped_cookie->real_write = writefn;
+  wrapped_cookie->real_seek = seekfn;
+  wrapped_cookie->real_flush = flushfn;
+  wrapped_cookie->real_close = closefn;
+
+  __sanitizer_FILE *res = REAL(funopen2)(wrapped_cookie,
+                                         readfn  ? wrapped_read2  : nullptr,
+                                         writefn ? wrapped_write2 : nullptr,
+                                         seekfn  ? wrapped_seek2  : nullptr,
+                                         flushfn ? wrapped_flush2 : nullptr,
+                                         closefn ? wrapped_close2 : nullptr);
+  if (res) unpoison_file(res);
+  return res;
+}
+#define INIT_FUNOPEN2 COMMON_INTERCEPT_FUNCTION(funopen2)
+#else
+#define INIT_FUNOPEN2
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map =
@@ -9416,6 +9571,8 @@
   INIT_POPEN;
   INIT_POPENVE;
   INIT_PCLOSE;
+  INIT_FUNOPEN;
+  INIT_FUNOPEN2;
 
   INIT___PRINTF_CHK;
 }
Index: lib/sanitizer_common/sanitizer_platform_interceptors.h
===================================================================
--- lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -549,5 +549,7 @@
 #define SANITIZER_INTERCEPT_POPEN SI_POSIX
 #define SANITIZER_INTERCEPT_POPENVE SI_NETBSD
 #define SANITIZER_INTERCEPT_PCLOSE SI_POSIX
+#define SANITIZER_INTERCEPT_FUNOPEN SI_NETBSD
+#define SANITIZER_INTERCEPT_FUNOPEN2 SI_NETBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H
Index: lib/sanitizer_common/sanitizer_platform_limits_netbsd.h
===================================================================
--- lib/sanitizer_common/sanitizer_platform_limits_netbsd.h
+++ lib/sanitizer_common/sanitizer_platform_limits_netbsd.h
@@ -2319,6 +2319,7 @@
   void *hash;
   uptr key_counter;
 };
+
 }  // namespace __sanitizer
 
 #define CHECK_TYPE_SIZE(TYPE) \