GeezerVison

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          Rename the news file to appease the Bedevere bot.

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🤖 New build scheduled with the buildbot fleet by @tiran for commit 0504ecb 🤖

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bedevere-bot removed the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label


          hexadecimal spelling =)

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gpshead marked this pull request as ready for review

September 2, 2022 16:54

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gpshead commented Sep 4, 2022

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wait for #96537 to be integrated into this PR before merging, i'll remove the do-not-merge label then.

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gpshead added the DO-NOT-MERGE label

gpshead and others added 5 commits

September 3, 2022 23:18


          doc typo: limitation

52f2c26

python#96542


          Misc: Fix a typo in the header comment.

510349b


          remove unneeded doc note on float.as_integer_ratio

ac99726

Per mdickinson@'s comment on the main branch PR.


          pythongh-95778: Correctly pre-check for int-to-str conversion (python…

17bd053

…#96537)

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: pythongh-95778 -->
* Issue: pythongh-95778
<!-- /gh-issue-number -->

Co-authored-by: Gregory P. Smith [Google LLC] <[email protected]>


          Use the 3.8 Get API for it to compile.

c9212d5

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🤖 New build scheduled with the buildbot fleet by @gpshead for commit c9212d5 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

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bedevere-bot removed the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label

ambv commented Sep 5, 2022

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@tiran can wasm32 failures be ignored here? This is a 3.8 backport and that version is not supported on WASM?

Those fail to build with errors like Invalid configuration wasm32-unknown-emscripten': system emscripten' not recognized , configure: error: cross build not supported for wasm32-unknown-emscripten, and configure: WARNING: unrecognized options: --with-emscripten-target, --enable-wasm-dynamic-linking, --disable-wasm-pthreads.

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ambv commented Sep 5, 2022

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Unfortunately, there are legitimate failures here.

Arch ASAN Debug https://buildbot.python.org/all/#/builders/586/builds/778:

0:24:11 load avg: 1.56 Re-running test_crypt in verbose mode
Fatal Python error: Segmentation fault

Arch ASAN https://buildbot.python.org/all/#/builders/581/builds/779:

==1967496==ERROR: AddressSanitizer: heap-use-after-free on address 0x60c000459a62 at pc 0x55c4e355a2eb bp 0x7ffd1eb1aec0 sp 0x7ffd1eb1aeb0

Arch USAN https://buildbot.python.org/all/#/builders/720/builds/676:

/buildbot/buildarea/pull_request.pablogsal-arch-x86_64.clang-ubsan/build/Modules/_sha3/kcp/KeccakP-1600-opt64.c:467:9: runtime error: load of misaligned address 0x555beeca9b27 for type 'UINT64' (aka 'unsigned long'), which requires 8 byte alignment

FreeBSD Shared https://buildbot.python.org/all/#/builders/203/builds/821:

ModuleNotFoundError: No module named '_sysconfigdata_d_freebsd14_x86_64-unknown-freebsd14'

s390x https://buildbot.python.org/all/#/builders/111/builds/784:

  File "/home/dje/cpython-buildarea/pull_request.edelsohn-fedora-z.clang/build/Lib/test/pickletester.py", line 3273 in __getattr__
  File "/home/dje/cpython-buildarea/pull_request.edelsohn-fedora-z.clang/build/Lib/test/pickletester.py", line 3273 in __getattr__
  File "/home/dje/cpython-buildarea/pull_request.edelsohn-fedora-z.clang/build/Lib/test/pickletester.py", line 3273 in __getattr__
  ...
make: *** [Makefile:1173: buildbottest] Segmentation fault (core dumped)

Gentoo with X https://buildbot.python.org/all/#/builders/344/builds/803:

FAIL: test_up_at_top (test.test_gdb.StackNavigationTests)
Verify handling of "py-up" at the top of the stack

At least the ASAN and USAN failures are definitely related to this change, the others might be related indirectly.

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ambv mentioned this pull request

[3.7] gh-95778: CVE-2020-10735: Prevent DoS by very large int() #96504

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gpshead commented Sep 5, 2022

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what makes you think those are related to this change?

Arch ASAN 3.8 both: https://buildbot.python.org/all/#/builders/590 and https://buildbot.python.org/all/#/builders/580 show red for six months on 3.8.

and Arch USAN has not 3.8 bot and history at all.

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gpshead commented Sep 5, 2022

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If you want a baseline for those bots on 3.8 with no changes, I ran them via #96586.

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ypankovych approved these changes

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ambv commented Sep 5, 2022

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We looked into this. 3.7 and 3.8 are typically not running address and undefined behavior sanitizers on buildbots. The label-driven trigger on PRs is overly broad and runs configurations that aren't used by us for the oldest branches in regular testing. At least 3.8 fails ASAN and UBSAN without #96503 applied as well. I'm landing this.

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ambv merged commit b5e331f into python:3.8

bedevere-bot removed the awaiting core review label