From c49e0df2d7b3b69e3d7ce2ef8a277915b3e3c84c Mon Sep 17 00:00:00 2001 From: rhe Date: Tue, 13 Sep 2016 07:08:15 +0000 Subject: string.c: fix buffer overflow check condition in rb_str_set_len() * string.c (rb_str_set_len): The buffer overflow check is wrong. The space for termlen is allocated outside the capacity returned by rb_str_capacity(). This fixes r41920 ("string.c: multi-byte terminator", 2013-07-11). [ruby-core:77257] [Bug #12757] * test/-ext-/string/test_set_len.rb (test_capacity_equals_to_new_size): Test for this change. Applying only the test will trigger [BUG]. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56148 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ChangeLog | 10 ++++++++++ string.c | 2 +- test/-ext-/string/test_set_len.rb | 9 +++++++++ 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index 5b1a84a710..920a11cada 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +Tue Sep 13 16:07:26 2016 Kazuki Yamaguchi + + * string.c (rb_str_set_len): The buffer overflow check is wrong. The + space for termlen is allocated outside the capacity returned by + rb_str_capacity(). This fixes r41920 ("string.c: multi-byte + terminator", 2013-07-11). [ruby-core:77257] [Bug #12757] + + * test/-ext-/string/test_set_len.rb (test_capacity_equals_to_new_size): + Test for this change. Applying only the test will trigger [BUG]. + Tue Sep 13 06:03:34 2016 NARUSE, Yui * common.mk (benchmark): fix lib path. diff --git a/string.c b/string.c index 59c44ca4ba..4197a174fb 100644 --- a/string.c +++ b/string.c @@ -2497,7 +2497,7 @@ rb_str_set_len(VALUE str, long len) if (STR_SHARED_P(str)) { rb_raise(rb_eRuntimeError, "can't set length of shared string"); } - if (len + termlen - 1 > (capa = (long)rb_str_capacity(str))) { + if (len > (capa = (long)str_capacity(str, termlen))) { rb_bug("probable buffer overflow: %ld for %ld", len, capa); } STR_SET_LEN(str, len); diff --git a/test/-ext-/string/test_set_len.rb b/test/-ext-/string/test_set_len.rb index 1c5252a5f6..58f51012fb 100644 --- a/test/-ext-/string/test_set_len.rb +++ b/test/-ext-/string/test_set_len.rb @@ -23,4 +23,13 @@ class Test_StrSetLen < Test::Unit::TestCase assert_equal("abc", @s1.set_len(3)) } end + + def test_capacity_equals_to_new_size + bug12757 = "[ruby-core:77257] [Bug #12757]" + # fill to ensure capacity does not decrease with force_encoding + str = Bug::String.new("\x00" * 128, capacity: 128) + str.force_encoding("UTF-32BE") + assert_equal 128, Bug::String.capacity(str) + assert_equal 127, str.set_len(127).bytesize, bug12757 + end end -- cgit v1.2.3