以下のように、ruby -v で変なところを読むようです。
% valgrind ./ruby -v
==15134== Memcheck, a memory error detector.
==15134== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al.
==15134== Using LibVEX rev 1854, a library for dynamic binary translation.
==15134== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP.
==15134== Using valgrind-3.3.1-Debian, a dynamic binary instrumentation framework.
==15134== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al.
==15134== For more details, rerun with: -v
==15134==
==15134== Invalid read of size 4
==15134== at 0x813DF26: vm_push_frame (vm_insnhelper.c:32)
==15134== by 0x814EEC1: th_init2 (vm.c:1742)
==15134== by 0x814F93F: Init_BareVM (vm.c:2086)
==15134== by 0x805DF8F: ruby_init (eval.c:54)
==15134== by 0x805D04E: main (main.c:34)
==15134== Address 0x4267164 is 4 bytes after a block of size 524,288 alloc'd
==15134== at 0x4023D6E: malloc (vg_replace_malloc.c:207)
==15134== by 0x806365E: vm_xmalloc (gc.c:657)
==15134== by 0x806380C: ruby_xmalloc2 (gc.c:747)
==15134== by 0x814E959: thread_recycle_stack (vm.c:1552)
==15134== by 0x814EE53: th_init2 (vm.c:1738)
==15134== by 0x814F93F: Init_BareVM (vm.c:2086)
==15134== by 0x805DF8F: ruby_init (eval.c:54)
==15134== by 0x805D04E: main (main.c:34)
ruby 1.9.2dev (2009-11-07 trunk 25681) [i686-linux]
==15134==
==15134== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 23 from 1)
==15134== malloc/free: in use at exit: 311,896 bytes in 11,805 blocks.
==15134== malloc/free: 11,907 allocs, 102 frees, 1,051,073 bytes allocated.
==15134== For counts of detected errors, rerun with: -v
==15134== searching for pointers to 11,805 not-freed blocks.
==15134== checked 393,272 bytes.
==15134==
==15134== LEAK SUMMARY:
==15134== definitely lost: 210,278 bytes in 8,694 blocks.
==15134== possibly lost: 0 bytes in 0 blocks.
==15134== still reachable: 101,618 bytes in 3,111 blocks.
==15134== suppressed: 0 bytes in 0 blocks.
==15134== Rerun with --leak-check=full to see details of leaked memory.
--
[田中 哲][たなか あきら][Tanaka Akira]
