Fix multiplying a list by an integer (list *= int): detect the
integer overflow when the new allocated length is close to the
maximum size. Issue reported by Jordan Limor.
list_resize() now checks for integer overflow before multiplying the
new allocated length by the list item size (sizeof(PyObject*)).
(cherry picked from commit a5f092f3c4)
Co-authored-by: Victor Stinner <vstinner@python.org>
When ValueError is raised if an integer is larger than the limit,
mention sys.set_int_max_str_digits() in the error message.
(cherry picked from commit e841ffc915)
Co-authored-by: Victor Stinner <vstinner@python.org>
- On WASI `ENOTCAPABLE` is now mapped to `PermissionError`.
- The `errno` modules exposes the new error number.
- `getpath.py` now ignores `PermissionError` when it cannot open landmark
files `pybuilddir.txt` and `pyenv.cfg`.
Converting a large enough `int` to a decimal string raises `ValueError` as expected. However, the raise comes _after_ the quadratic-time base-conversion algorithm has run to completion. For effective DOS prevention, we need some kind of check before entering the quadratic-time loop. Oops! =)
The quick fix: essentially we catch _most_ values that exceed the threshold up front. Those that slip through will still be on the small side (read: sufficiently fast), and will get caught by the existing check so that the limit remains exact.
The justification for the current check. The C code check is:
```c
max_str_digits / (3 * PyLong_SHIFT) <= (size_a - 11) / 10
```
In GitHub markdown math-speak, writing $M$ for `max_str_digits`, $L$ for `PyLong_SHIFT` and $s$ for `size_a`, that check is:
$$\left\lfloor\frac{M}{3L}\right\rfloor \le \left\lfloor\frac{s - 11}{10}\right\rfloor$$
From this it follows that
$$\frac{M}{3L} < \frac{s-1}{10}$$
hence that
$$\frac{L(s-1)}{M} > \frac{10}{3} > \log_2(10).$$
So
$$2^{L(s-1)} > 10^M.$$
But our input integer $a$ satisfies $|a| \ge 2^{L(s-1)}$, so $|a|$ is larger than $10^M$. This shows that we don't accidentally capture anything _below_ the intended limit in the check.
<!-- gh-issue-number: gh-95778 -->
* Issue: gh-95778
<!-- /gh-issue-number -->
Co-authored-by: Gregory P. Smith [Google LLC] <greg@krypto.org>
(cherry picked from commit b126196838)
Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
Integer to and from text conversions via CPython's bignum `int` type is not safe against denial of service attacks due to malicious input. Very large input strings with hundred thousands of digits can consume several CPU seconds.
This PR comes fresh from a pile of work done in our private PSRT security response team repo.
This backports https://github.com/python/cpython/pull/96499 aka 511ca94520
Signed-off-by: Christian Heimes [Red Hat] <christian@python.org>
Tons-of-polishing-up-by: Gregory P. Smith [Google] <greg@krypto.org>
Reviews via the private PSRT repo via many others (see the NEWS entry in the PR).
<!-- gh-issue-number: gh-95778 -->
* Issue: gh-95778
<!-- /gh-issue-number -->
I wrote up [a one pager for the release managers](https://docs.google.com/document/d/1KjuF_aXlzPUxTK4BMgezGJ2Pn7uevfX7g0_mvgHlL7Y/edit#).
This PR fixes the error message from float(s) in the case where s contains only whitespace.
(cherry picked from commit 97e9cfa75a)
Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Stanley <46876382+slateny@users.noreply.github.com>
Co-authored-by: Mark Shannon <mark@hotpy.org>
* Add test for inheriting explicit __dict__ and weakref.
* Restore 3.10 behavior for multiple inheritance of C extension classes that store their dictionary at the end of the struct.
Co-authored-by: Serhiy Storchaka <3659035+serhiy-storchaka@users.noreply.github.com>
(cherry picked from commit 6442a9dd21)
Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Because of the way wrap_descr_get is written, the second argument
to __get__ methods implemented through the wrapper is always
optional.
(cherry picked from commit 4e08fbcfdf)
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Move the follow functions and type from frameobject.h to pyframe.h,
so the standard <Python.h> provide frame getter functions:
* PyFrame_Check()
* PyFrame_GetBack()
* PyFrame_GetBuiltins()
* PyFrame_GetGenerator()
* PyFrame_GetGlobals()
* PyFrame_GetLasti()
* PyFrame_GetLocals()
* PyFrame_Type
Remove #include "frameobject.h" from many C files. It's no longer
needed.
(cherry picked from commit 27b9894033)
list[int].__class__ returned type, and isinstance(list[int], type)
returned True. It caused numerous problems in code that checks
isinstance(x, type).
(cherry picked from commit f9433fff47)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Classes ReferenceType, ProxyType and CallableProxyType have now correct
atrtributes __module__, __name__ and __qualname__.
It makes them (types, not instances) pickleable.
(cherry picked from commit 8352e322e8)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
(cherry picked from commit caa279d6fd)
This was added for bpo-40514 (gh-84694) to test out a per-interpreter GIL. However, it has since proven unnecessary to keep the experiment in the repo. (It can be done as a branch in a fork like normal.) So here we are removing:
* the configure option
* the macro
* the code enabled by the macro
Automerge-Triggered-By: GH:ericsnowcurrently
Currently, calling Py_EnterRecursiveCall() and
Py_LeaveRecursiveCall() may use a function call or a static inline
function call, depending if the internal pycore_ceval.h header file
is included or not. Use a different name for the static inline
function to ensure that the static inline function is always used in
Python internals for best performance. Similar approach than
PyThreadState_GET() (function call) and _PyThreadState_GET() (static
inline function).
* Rename _Py_EnterRecursiveCall() to _Py_EnterRecursiveCallTstate()
* Rename _Py_LeaveRecursiveCall() to _Py_LeaveRecursiveCallTstate()
* pycore_ceval.h: Rename Py_EnterRecursiveCall() to
_Py_EnterRecursiveCall() and Py_LeaveRecursiveCall() and
_Py_LeaveRecursiveCall()
Replace "(PyCFunction)(void(*)(void))func" cast with
_PyCFunction_CAST(func).
Change generated by the command:
sed -i -e \
's!(PyCFunction)(void(\*)(void)) *\([A-Za-z0-9_]\+\)!_PyCFunction_CAST(\1)!g' \
$(find -name "*.c")
If the error handler returns position less or equal than the starting
position of non-encodable characters, most of built-in encoders didn't
properly re-size the output buffer. This led to out-of-bounds writes,
and segfaults.
Reduce the complexity from O((M+N)^2) to O(M*N), where M and N are the length
of __args__ for both operands (1 for operand which is not a UnionType).
As a consequence, the complexity of parameter substitution in UnionType has
been reduced from O(N^3) to O(N^2).
Co-authored-by: Yurii Karabas <1998uriyyo@gmail.com>
Move the following API from Include/opcode.h (public C API) to a new
Include/internal/pycore_opcode.h header file (internal C API):
* EXTRA_CASES
* _PyOpcode_Caches
* _PyOpcode_Deopt
* _PyOpcode_Jump
* _PyOpcode_OpName
* _PyOpcode_RelativeJump
* Stores all location info in linetable to conform to PEP 626.
* Remove column table from code objects.
* Remove end-line table from code objects.
* Document new location table format
Python 3.11 now uses C11 standard which adds static_assert()
to <assert.h>.
* In pytime.c, replace Py_BUILD_ASSERT() with preprocessor checks on
SIZEOF_TIME_T with #error.
* On macOS, py_mach_timebase_info() now accepts timebase members with
the same size than _PyTime_t.
* py_get_monotonic_clock() now saturates GetTickCount64() to
_PyTime_MAX: GetTickCount64() is unsigned, whereas _PyTime_t is
signed.
The left-hand side expression of the if-check can be converted to a
constant by the compiler, but the addition on the right-hand side is
performed during runtime.
Move the addition from the right-hand side to the left-hand side by
turning it into a subtraction there. Since the values are known to
be large enough to not turn negative, this is a safe operation.
Prevents a very unlikely integer overflow on 32 bit systems.
Fixes GH-91421.
Miss Islington (bot)