From 69f9992ed41920389d4185141a14f02f89a4d306 Mon Sep 17 00:00:00 2001
From: usa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 12 Apr 2022 11:49:45 +0000
Subject: [PATCH] Fix dtoa buffer overrun

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_6@67957 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 test/ruby/test_float.rb | 18 ++++++++++++++++++
 util.c                  |  3 ++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/test/ruby/test_float.rb b/test/ruby/test_float.rb
index 7fabfd3..78c63c2 100644
--- a/test/ruby/test_float.rb
+++ b/test/ruby/test_float.rb
@@ -171,6 +171,24 @@ class TestFloat < Test::Unit::TestCase
       assert_raise(ArgumentError, n += z + "A") {Float(n)}
       assert_raise(ArgumentError, n += z + ".0") {Float(n)}
     end
+
+    x = nil
+    2000.times do
+      x = Float("0x"+"0"*30)
+      break unless x == 0.0
+    end
+    assert_equal(0.0, x, ->{"%a" % x})
+    x = nil
+    2000.times do
+      begin
+        x = Float("0x1."+"0"*270)
+      rescue ArgumentError => e
+        raise unless /"0x1\.0{270}"/ =~ e.message
+      else
+        break
+      end
+    end
+    assert_nil(x, ->{"%a" % x})
   end
 
   def test_divmod
diff --git a/util.c b/util.c
index 2222744..f1d910f 100644
--- a/util.c
+++ b/util.c
@@ -2046,6 +2046,7 @@ break2:
 	    if (!*++s || !(s1 = strchr(hexdigit, *s))) goto ret0;
 	    if (*s == '0') {
 		while (*++s == '0');
+		if (!*s) goto ret;
 		s1 = strchr(hexdigit, *s);
 	    }
 	    if (s1 != NULL) {
@@ -2068,7 +2069,7 @@ break2:
 		for (; *s && (s1 = strchr(hexdigit, *s)); ++s) {
 		    adj += aadj * ((s1 - hexdigit) & 15);
 		    if ((aadj /= 16) == 0.0) {
-			while (strchr(hexdigit, *++s));
+			while (*++s && strchr(hexdigit, *s));
 			break;
 		    }
 		}
-- 
1.8.3.1

