Index: lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -5694,9 +5694,15 @@
 void unpoison_file(__sanitizer_FILE *fp) {
 #if SANITIZER_HAS_STRUCT_FILE
   COMMON_INTERCEPTOR_INITIALIZE_RANGE(fp, sizeof(*fp));
+#if SANITIZER_NETBSD
+  if (fp->_bf._base && fp->_bf._size > 0)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(fp->_bf._base,
+                                        fp->_bf._size);
+#else
   if (fp->_IO_read_base && fp->_IO_read_base < fp->_IO_read_end)
     COMMON_INTERCEPTOR_INITIALIZE_RANGE(fp->_IO_read_base,
                                         fp->_IO_read_end - fp->_IO_read_base);
+#endif
 #endif  // SANITIZER_HAS_STRUCT_FILE
 }
 #endif
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
@@ -446,8 +446,36 @@
   uptr we_nbytes;
 };
 
-typedef char __sanitizer_FILE;
-#define SANITIZER_HAS_STRUCT_FILE 0
+struct __sanitizer_FILE {
+  unsigned char *_p;
+  int _r;
+  int _w;
+  unsigned short _flags;
+  short _file;
+  struct {
+    unsigned char *_base;
+    int _size;
+  } _bf;
+  int _lbfsize;
+  void *_cookie;
+  int (*_close)(void *ptr);
+  u64 (*_read)(void *, void *, uptr);
+  u64 (*_seek)(void *, u64, int);
+  uptr (*_write)(void *, const void *, uptr);
+  struct {
+    unsigned char *_base;
+    int _size;
+  } _ext;
+  unsigned char *_up;
+  int _ur;
+  unsigned char _ubuf[3];
+  unsigned char _nbuf[1];
+  int (*_flush)(void *ptr);
+  char _lb_unused[sizeof(uptr)];
+  int _blksize;
+  u64 _offset;
+};
+#define SANITIZER_HAS_STRUCT_FILE 1
 
 extern int shmctl_ipc_stat;
 
Index: lib/sanitizer_common/sanitizer_platform_limits_netbsd.cc
===================================================================
--- lib/sanitizer_common/sanitizer_platform_limits_netbsd.cc
+++ lib/sanitizer_common/sanitizer_platform_limits_netbsd.cc
@@ -2224,6 +2224,29 @@
 CHECK_SIZE_AND_OFFSET(wordexp_t, we_wordv);
 CHECK_SIZE_AND_OFFSET(wordexp_t, we_offs);
 
+COMPILER_CHECK(sizeof(__sanitizer_FILE) <= sizeof(FILE));
+CHECK_SIZE_AND_OFFSET(FILE, _p);
+CHECK_SIZE_AND_OFFSET(FILE, _r);
+CHECK_SIZE_AND_OFFSET(FILE, _w);
+CHECK_SIZE_AND_OFFSET(FILE, _flags);
+CHECK_SIZE_AND_OFFSET(FILE, _file);
+CHECK_SIZE_AND_OFFSET(FILE, _bf);
+CHECK_SIZE_AND_OFFSET(FILE, _lbfsize);
+CHECK_SIZE_AND_OFFSET(FILE, _cookie);
+CHECK_SIZE_AND_OFFSET(FILE, _close);
+CHECK_SIZE_AND_OFFSET(FILE, _read);
+CHECK_SIZE_AND_OFFSET(FILE, _seek);
+CHECK_SIZE_AND_OFFSET(FILE, _write);
+CHECK_SIZE_AND_OFFSET(FILE, _ext);
+CHECK_SIZE_AND_OFFSET(FILE, _up);
+CHECK_SIZE_AND_OFFSET(FILE, _ur);
+CHECK_SIZE_AND_OFFSET(FILE, _ubuf);
+CHECK_SIZE_AND_OFFSET(FILE, _nbuf);
+CHECK_SIZE_AND_OFFSET(FILE, _flush);
+CHECK_SIZE_AND_OFFSET(FILE, _lb_unused);
+CHECK_SIZE_AND_OFFSET(FILE, _blksize);
+CHECK_SIZE_AND_OFFSET(FILE, _offset);
+
 CHECK_TYPE_SIZE(tm);
 CHECK_SIZE_AND_OFFSET(tm, tm_sec);
 CHECK_SIZE_AND_OFFSET(tm, tm_min);
Index: lib/tsan/rtl/tsan_interceptors.cc
===================================================================
--- lib/tsan/rtl/tsan_interceptors.cc
+++ lib/tsan/rtl/tsan_interceptors.cc
@@ -42,16 +42,12 @@
 
 #if SANITIZER_NETBSD
 #define dirfd(dirp) (*(int *)(dirp))
-#define fileno_unlocked fileno
+#define fileno_unlocked(fp) \
+  (((__sanitizer_FILE*)fp)->_file == -1 ? -1 : \
+   (int)(unsigned short)(((__sanitizer_FILE*)fp)->_file))  // NOLINT
 
-#if _LP64
-#define __sF_size 152
-#else
-#define __sF_size 88
-#endif
-
-#define stdout ((char*)&__sF + (__sF_size * 1))
-#define stderr ((char*)&__sF + (__sF_size * 2))
+#define stdout ((__sanitizer_FILE*)&__sF[1])
+#define stderr ((__sanitizer_FILE*)&__sF[2])
 
 #define nanosleep __nanosleep50
 #define vfork __vfork14
@@ -96,8 +92,8 @@
 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
 extern "C" void *pthread_self();
 extern "C" void _exit(int status);
-extern "C" int fileno_unlocked(void *stream);
 #if !SANITIZER_NETBSD
+extern "C" int fileno_unlocked(void *stream);
 extern "C" int dirfd(void *dirp);
 #endif
 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_NETBSD