Created on 2017-01-30 17:30 by RazerM, last changed 2018-05-28 22:31 by steve.dower. This issue is now closed.
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| msg286495 - (view) | Author: Frazer McLean (RazerM) | Date: 2017-01-30 17:30 | |
On 3.5.2 and 3.5.3, but not 3.4.3 or 2.7.10 (Windows 64-bit), the third line causes Python to crash with exit code 0xC0000417.
import msvcrt
fp = open('file.txt', 'w')
msvcrt.locking(fp.fileno(), msvcrt.LK_NBLCK, -1)
print('End')
I came across this in the portalocker module. I don't think -1 is a valid third argument, but it doesn't raise an exception on Python 3.4 or 2.7.
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| msg286500 - (view) | Author: Frazer McLean (RazerM) | Date: 2017-01-30 23:09 | |
I ran it on AppVeyor to double check, the crash appears from 3.5 onwards as I saw on my computer. https://ci.appveyor.com/project/RazerM/issue29392/build/3 |
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| msg286501 - (view) | Author: Eryk Sun (eryksun) *  |
Date: 2017-01-30 23:40 | |
The old CRT doesn't do any parameter validation on the nbytes parameter. It just passes it directly to Windows LockFile as follows:
LockFile((HANDLE)_get_osfhandle(fh), lockoffset, 0L, nbytes, 0L)
which is locking (DWORD)-1 bytes, i.e. 0xFFFFFFFF. This allows users to sneakily lock more than 2 GiB by passing a negative value. Python could do its own validation in 2.7 to raise an exception for negative values, but I think it's too late; that ship has sailed.
The parameter is validated by the new CRT in 3.5+, which limits nbytes to non-negative values. There we need the _Py_BEGIN_SUPPRESS_IPH and _Py_END_SUPPRESS_IPH macros to handle the failed call without crashing the process.
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| msg287003 - (view) | Author: Roundup Robot (python-dev) |
Date: 2017-02-04 23:06 | |
New changeset f48bdcd02b57 by Steve Dower in branch '3.5': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://hg.python.org/cpython/rev/f48bdcd02b57 New changeset 15bbb18d87fd by Steve Dower in branch '3.6': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://hg.python.org/cpython/rev/15bbb18d87fd New changeset fb6a48fa8da3 by Steve Dower in branch 'default': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://hg.python.org/cpython/rev/fb6a48fa8da3 |
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| msg287012 - (view) | Author: Roundup Robot (python-dev) |
Date: 2017-02-05 00:00 | |
New changeset cb0c9718f7bd13df67b0d7df88b6f5b197ef05a7 by Steve Dower in branch '3.5': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://github.com/python/cpython/commit/cb0c9718f7bd13df67b0d7df88b6f5b197ef05a7 |
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| msg287016 - (view) | Author: Roundup Robot (python-dev) |
Date: 2017-02-05 00:00 | |
New changeset cb0c9718f7bd13df67b0d7df88b6f5b197ef05a7 by Steve Dower in branch 'master': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://github.com/python/cpython/commit/cb0c9718f7bd13df67b0d7df88b6f5b197ef05a7 New changeset ed8b523b9f6495806a38262ca9d1676bf7d5e830 by Steve Dower in branch 'master': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://github.com/python/cpython/commit/ed8b523b9f6495806a38262ca9d1676bf7d5e830 New changeset 01c3bdbb25068e7558ff8f275d0ed22c9f4e6b32 by Steve Dower in branch 'master': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://github.com/python/cpython/commit/01c3bdbb25068e7558ff8f275d0ed22c9f4e6b32 |
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| msg287021 - (view) | Author: Roundup Robot (python-dev) |
Date: 2017-02-05 00:00 | |
New changeset ed8b523b9f6495806a38262ca9d1676bf7d5e830 by Steve Dower in branch '3.6': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://github.com/python/cpython/commit/ed8b523b9f6495806a38262ca9d1676bf7d5e830 New changeset cb0c9718f7bd13df67b0d7df88b6f5b197ef05a7 by Steve Dower in branch '3.6': Issue #29392: Prevent crash when passing invalid arguments into msvcrt module. https://github.com/python/cpython/commit/cb0c9718f7bd13df67b0d7df88b6f5b197ef05a7 |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2018-05-28 22:31:29 | steve.dower | set | status: open -> closed |
| 2017-02-05 00:00:34 | python-dev | set | messages: + msg287021 |
| 2017-02-05 00:00:31 | python-dev | set | messages: + msg287016 |
| 2017-02-05 00:00:29 | python-dev | set | messages: + msg287012 |
| 2017-02-04 23:06:23 | steve.dower | set | assignee: steve.dower resolution: fixed stage: needs patch -> resolved |
| 2017-02-04 23:06:04 | python-dev | set | nosy:
+ python-dev messages: + msg287003 |
| 2017-01-30 23:51:18 | eryksun | set | stage: needs patch versions: + Python 3.6, Python 3.7 |
| 2017-01-30 23:40:32 | eryksun | set | nosy:
+ eryksun messages: + msg286501 |
| 2017-01-30 23:09:43 | RazerM | set | messages: + msg286500 |
| 2017-01-30 17:30:26 | RazerM | create | |