[New-bugs-announce] [issue6402] Crash after attempt to set the error indicator via PyErr_SetString()

[Jan Lieskovsky]

New submission from Jan Lieskovsky <iankko at seznam.cz>:

Hello guys,

  i am experiencing segmentation fault, when trying to set the
error indicator via the PyErr_SetString() method called from C source.
This occurs for all Python exceptions, as documented in:

    http://docs.python.org/c-api/exceptions.html

Checked Python-2.6.2, also Python-2.4.1 - the crash is present
there (wondering what's wrong with the provided reproducer).

Scenario:
--------
tar xvzf pyexceptions-sample.tar.gz
cd pyexceptions-sample
make
./pyexceptionssample -> 
Segmentation fault (core dumped)

Note: Doesn't matter if compiled with libpython2.6.a or libpython2.4.so,
      the crash is still there.

Here is the most interesting part of the backtrace (the whole
coredump also attached).

gdb ./pyexceptions-sample core.31283

Core was generated by `./pyexceptions-sample'.
Program terminated with signal 11, Segmentation fault.
[New process 31283]
#0  PyErr_Restore (type=0x60000000000058f0, value=0x2000000000435030,
traceback=0x0) at Python/errors.c:39
39		oldtype = tstate->curexc_type;

(gdb) bt
#0  PyErr_Restore (type=0x60000000000058f0, value=0x2000000000435030,
traceback=0x0) at Python/errors.c:39
#1  0x4000000000125180 in PyErr_SetString (exception=0x60000000000058f0,
string=<value optimized out>) at Python/errors.c:57
#2  0x4000000000005eb0 in check_value ()
#3  0x4000000000006670 in main ()

(gdb) info args
type = (PyObject *) 0x60000000000058f0
value = (PyObject *) 0x2000000000435030
traceback = (PyObject *) 0x0

(gdb) info locals
tstate = (PyThreadState *) 0x0
oldtype = <value optimized out>
oldvalue = <value optimized out>
oldtraceback = <value optimized out>

(Looks like NULL ptr dereference in tstate = (PyThreadState *)).

Could you please have a look?

Thanks && regards, Jan.
--
Jan iankko Lieskovsky

----------
components: Interpreter Core
files: pyexceptions-sample.tar.gz
messages: 90026
nosy: iankko
severity: normal
status: open
title: Crash after attempt to set the error indicator via PyErr_SetString()
type: crash
versions: Python 2.4, Python 2.5, Python 2.6
Added file: http://bugs.python.org/file14428/pyexceptions-sample.tar.gz

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue6402>
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