[3.15] gh-153570: Fix use-after-free in bytearray.take_bytes() with a reentrant __index__ (GH-153572) - #154648
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…reentrant __index__ (pythonGH-153572) bytearray.take_bytes() cached the size before the argument's __index__ call and used it for the bounds check and the buffer reads, so an __index__ that resizes the bytearray left it reading freed memory. Re-read the size after __index__, matching bytearray.__setitem__ (pythonGH-91153). (cherry picked from commit ee21d99) Co-authored-by: tonghuaroot (童话) <tonghuaroot@gmail.com>
This was referenced Jul 24, 2026
cmaloney
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Jul 24, 2026
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bytearray.take_bytes() cached the size before the argument's index call and
used it for the bounds check and the buffer reads, so an index that resizes
the bytearray left it reading freed memory. Re-read the size after index,
matching bytearray.setitem (GH-91153).
(cherry picked from commit ee21d99)
Co-authored-by: tonghuaroot (童话) tonghuaroot@gmail.com