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bpo-45329: Fix freed memory access in pyexpat.c#28649

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serhiy-storchaka merged 5 commits intopython:mainfrom
y-tag:pyexpat-freed-memory
Oct 2, 2021
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bpo-45329: Fix freed memory access in pyexpat.c#28649
serhiy-storchaka merged 5 commits intopython:mainfrom
y-tag:pyexpat-freed-memory

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@y-tag y-tag commented Sep 30, 2021 •
edited by bedevere-bot
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https://bugs.python.org/issue45329

  • xmlparse_clear(self) calls clear_handlers(self, 0)
  • clear_handlers(self, 0) accesses self->itself
  • Therefore xmlparse_clear(self) would be done before XML_ParserFree(self->itself)

https://bugs.python.org/issue45329

@serhiy-storchaka serhiy-storchaka added needs backport to 3.9 needs backport to 3.10 only security fixes type-bug An unexpected behavior, bug, or error labels Oct 1, 2021
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serhiy-storchaka commented Oct 1, 2021

LGTM, but please add a NEWS entry. https://blurb-it.herokuapp.com/

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y-tag commented Oct 1, 2021

I found that the segmentation fault occurs with expat 2.2.0 or earlier.
Null check has been added to 2.2.1.
Since the expat included in this repositry has been updated to 2.4.1, the segmentation fault does not occur with it.
Some tests are failed with ./configure --with-system-expat on CentOS 7, which includes expat 2.1.0.

So this patch might be useful on system which uses old expat...

@serhiy-storchaka serhiy-storchaka merged commit 0742abd into python:main Oct 2, 2021
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miss-islington commented Oct 2, 2021

Thanks @y-tag for the PR, and @serhiy-storchaka for merging it 🌮🎉.. I'm working now to backport this PR to: 3.9, 3.10.
🐍🍒⛏🤖

miss-islington pushed a commit to miss-islington/cpython that referenced this pull request Oct 2, 2021
@y-tag @miss-islington
bpo-45329: Fix freed memory access in pyexpat.c (pythonGH-28649)
0e39c63 
(cherry picked from commit 0742abd)

Co-authored-by: TAGAMI Yukihiro <[email protected]>
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bedevere-bot commented Oct 2, 2021

GH-28692 is a backport of this pull request to the 3.10 branch.

@bedevere-bot bedevere-bot removed the needs backport to 3.10 only security fixes label Oct 2, 2021
miss-islington pushed a commit to miss-islington/cpython that referenced this pull request Oct 2, 2021
@y-tag @miss-islington
bpo-45329: Fix freed memory access in pyexpat.c (pythonGH-28649)
0c70829 
(cherry picked from commit 0742abd)

Co-authored-by: TAGAMI Yukihiro <[email protected]>
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bedevere-bot commented Oct 2, 2021

GH-28693 is a backport of this pull request to the 3.9 branch.

@y-tag y-tag deleted the pyexpat-freed-memory branch October 2, 2021 11:20
miss-islington added a commit that referenced this pull request Oct 2, 2021
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bpo-45329: Fix freed memory access in pyexpat.c (GH-28649)
22cf6a2 
(cherry picked from commit 0742abd)

Co-authored-by: TAGAMI Yukihiro <[email protected]>
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serhiy-storchaka commented Oct 2, 2021

Thank you for your contribution TAGAMI-san!

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y-tag commented Oct 2, 2021

Thank you too! 😃

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