Description of problem:
When running 'gem install rhc' on a RHEL 5.x machine (verified on 5.6 and 5.7), it encounters a buffer overflow error.  For example:


Version-Release number of selected component (if applicable):
Specific to RHEL 5.6+ and the packaged version of Ruby.

How reproducible:
Always

Steps to Reproduce:
1. Find a RHEL 5.6 machine
2. gem install rhc
  
Actual results:

[root@********-app1 ~]# gem install rhc
*** buffer overflow detected ***: /usr/bin/ruby terminated
======= Backtrace: =========
/lib64/libc.so.6(__chk_fail+0x2f)[0x30a78e803f]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(rb_syck_mktime+0x48e)[0x2b06c90dcc7e]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(yaml_org_handler+0x860)[0x2b06c90dd590]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(syck_defaultresolver_node_import+0x39)[0x2b06c90dd799]
/usr/lib64/libruby.so.1.8[0x30a883492e]
/usr/lib64/libruby.so.1.8[0x30a8834e48]
/usr/lib64/libruby.so.1.8[0x30a88353f2]
/usr/lib64/libruby.so.1.8(rb_funcall+0x85)[0x30a88356c5]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(rb_syck_load_handler+0x47)[0x2b06c90dc727]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(syck_hdlr_add_node+0x39)[0x2b06c90d84f9]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(syckparse+0xb45)[0x2b06c90d21f5]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(syck_parse+0x19)[0x2b06c90d6c19]
/usr/lib64/ruby/1.8/x86_64-linux/syck.so(syck_parser_load+0xed)[0x2b06c90dc59d]
/usr/lib64/libruby.so.1.8[0x30a883492e]
...


Expected results:
The gem installs successfully.

Additional info:

Speaking with vondruch, he thinks this might be solved with the following patch (we would need to backport to Ruby 1.8.5):

https://github.com/ruby/ruby/commit/65e137a74c1a6c1dddac44ca6f9d569828fb38d8#ext/syck/rubyext.c

Also, this isn't specific to the 'rhc' rubygem.  There are other examples of this behavior as well:

https://github.com/brianmario/yajl-ruby/issues/89
https://github.com/ezmobius/redis-rb/issues/131