diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -575,10 +575,12 @@
 #if SANITIZER_INTERCEPT_STRSTR || SANITIZER_INTERCEPT_STRCASESTR
 static inline void StrstrCheck(void *ctx, char *r, const char *s1,
                                const char *s2) {
-    uptr len1 = internal_strlen(s1);
-    uptr len2 = internal_strlen(s2);
-    COMMON_INTERCEPTOR_READ_STRING(ctx, s1, r ? r - s1 + len2 : len1 + 1);
-    COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, len2 + 1);
+  uptr len2 = internal_strlen(s2);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, len2 + 1);
+  if (len2 == 0 && !common_flags()->strict_string_checks)
+    return;
+  uptr len1 = internal_strlen(s1);
+  COMMON_INTERCEPTOR_READ_STRING(ctx, s1, r ? r - s1 + len2 : len1 + 1);
 }
 #endif
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp
--- a/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_libc.cpp
@@ -217,8 +217,10 @@
 
 char *internal_strstr(const char *haystack, const char *needle) {
   // This is O(N^2), but we are not using it in hot places.
-  uptr len1 = internal_strlen(haystack);
   uptr len2 = internal_strlen(needle);
+  if (len2 == 0)
+    return const_cast<char *>(haystack);
+  uptr len1 = internal_strlen(haystack);
   if (len1 < len2) return nullptr;
   for (uptr pos = 0; pos <= len1 - len2; pos++) {
     if (internal_memcmp(haystack + pos, needle, len2) == 0)
diff --git a/compiler-rt/test/sanitizer_common/TestCases/strstr.c b/compiler-rt/test/sanitizer_common/TestCases/strstr.c
--- a/compiler-rt/test/sanitizer_common/TestCases/strstr.c
+++ b/compiler-rt/test/sanitizer_common/TestCases/strstr.c
@@ -8,5 +8,9 @@
   char s2[] = "b";
   r = strstr(s1, s2);
   assert(r == s1 + 1);
+  char *s3 = NULL;
+  char *s4 = "";
+  char *p = strstr(s3, s4);
+  assert(p == NULL);
   return 0;
 }