[Bug libstdc++/43483] New: STL sort SIGSEV

[richardlee at snowshoefox dot com]

The STL sort implementation in stl_algo.h SIGSEVs under certain conditions due
to not checking the position of the __first and __last iterator positions.

Here is a diff between a working version and the buggy version in 4.4.1:

2228d2227
<       int len = __last - __first;
2231c2230
<         while (__first != __last && __comp(*__first, __pivot))
---
>         while (__comp(*__first, __pivot))
2233,2234c2232,2233
<         --__last; 
<         while (len-- > 0 && __comp(__pivot, *__last))
---
>         --__last;
>         while (__comp(__pivot, *__last))

The fix is to make sure __first and __last stays within the boundary of
[__first, __last).


-- 
           Summary: STL sort SIGSEV
           Product: gcc
           Version: 4.4.1
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: richardlee at snowshoefox dot com
  GCC host triplet: 2.6.31-20-generic #58-Ubuntu SMP x86_64 GNU/Linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43483