[cfe-dev] Sanitizer and "downcast of address 0xXX...XXX with insufficient space for an object of type '_Rb_tree_node' "

[David Blaikie]

On Thu, Aug 1, 2013 at 12:57 AM, Jeffrey Walton <noloader at gmail.com> wrote:
> Hi All,
>
> What is this finding trying to tell me.
>
> The iterator is a typedef for _Base_ptr, and the address of _M_header
> is a pointer.

What type is _M_header? How big is it? I think it's telling you that
_M_header is too small to possibly be a _Link_type.

>_Link_type is typedef'd as a _Rb_tree_node<_Tp>*. So I
> don't see a width problem.
>
> *****
> Testing ECDSA (InSiTo unit tests):
> ../usr/include/c++/4.2.1/bits/stl_tree.h:620:25: runtime error:
> downcast of address 0x7fff5598fe88 with insufficient space for an
> object of type '_Rb_tree_node' (aka '_Rb_tree_node<std::pair<const
> Botan::OID, std::basic_string<char> > >')
> 0x7fff5598fe88: note: pointer points here
>  00 00 00 00  00 00 00 00 00 00 00 00  10 a7 14 01 70 60 00 00  80 a7
> 14 01 70 60 00 00  c0 a5 14 01
>               ^
> *****
> From stl_tree.h:
>
>   618    iterator
>   619    end()
>   620    { return iterator(static_cast<_Link_type>(&this->_M_impl._M_header)); }
>
> *****
> OS X 10.8.3
>
> $ uname -a
> Darwin riemann.home.pvt 12.4.0 Darwin Kernel Version 12.4.0: Wed May
> 1 17:57:12 PDT 2013; root:xnu-2050.24.15~1/RELEASE_X86_64 x86_64
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