[Bug c/52236] New: segfault in program that results from compiling sha512-hash.c

["zooko at zooko dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52236

             Bug #: 52236
           Summary: segfault in program that results from compiling
                    sha512-hash.c
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zooko@zooko.com


Using this version of gcc-4.7.0 prerelease which is shipped in Fedora Rawhide:
4.7.0 20120126 (Red Hat 4.7.0-0.10), the resulting code segfaults. Valgrind
reports this:

==9709== Invalid read of size 1
==9709==    at 0xB4FEE70: crypto_hash_sha512 (sha512-hash.c:40)
==9709==    by 0xB4F8F23: crypto_sign_publickey (ed25519.c:30)
==9709==    by 0xB4F7EEB: ed25519_publickey (ed25519module.c:48)
==9709==    by 0x4F0A153: PyEval_EvalFrameEx (in
/usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4F0B7C0: PyEval_EvalCodeEx (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E9C2BA: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E78A1D: PyObject_Call (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E86EEF: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E78A1D: PyObject_Call (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4ECBC41: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4ECB8DB: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E78A1D: PyObject_Call (in /usr/lib64/libpython2.7.so.1.0)
==9709==  Address 0x0 is not stack'd, malloc'd or (recently) free'd
==9709== 
{
   <insert_a_suppression_name_here>
   Memcheck:Addr1
   fun:crypto_hash_sha512
   fun:crypto_sign_publickey
   fun:ed25519_publickey
   fun:PyEval_EvalFrameEx
   fun:PyEval_EvalCodeEx
   obj:/usr/lib64/libpython2.7.so.1.0
   fun:PyObject_Call
   obj:/usr/lib64/libpython2.7.so.1.0
   fun:PyObject_Call
   obj:/usr/lib64/libpython2.7.so.1.0
   obj:/usr/lib64/libpython2.7.so.1.0
   fun:PyObject_Call
}
==9709== 
==9709== Process terminating with default action of signal 11 (SIGSEGV)
==9709==  Access not within mapped region at address 0x0
==9709==    at 0xB4FEE70: crypto_hash_sha512 (sha512-hash.c:40)
==9709==    by 0xB4F8F23: crypto_sign_publickey (ed25519.c:30)
==9709==    by 0xB4F7EEB: ed25519_publickey (ed25519module.c:48)
==9709==    by 0x4F0A153: PyEval_EvalFrameEx (in
/usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4F0B7C0: PyEval_EvalCodeEx (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E9C2BA: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E78A1D: PyObject_Call (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E86EEF: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E78A1D: PyObject_Call (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4ECBC41: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4ECB8DB: ??? (in /usr/lib64/libpython2.7.so.1.0)
==9709==    by 0x4E78A1D: PyObject_Call (in /usr/lib64/libpython2.7.so.1.0)

More detail, including access to a buildbot which can reliably reproduce the
problem on Fedora Rawhide and demonstrate no such problem on several other
platforms, is here: https://tahoe-lafs.org/trac/pycryptopp/ticket/80