[3.13] gh-153539: Fix use-after-free in TextIOWrapper.tell() with a reentrant decoder (GH-153540) - #156195
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serhiy-storchaka merged 1 commit intoAug 21, 2026
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…entrant decoder (pythonGH-153540) TextIOWrapper.tell() used a borrowed next_input from the snapshot across the decoder's getstate/decode/setstate calls, so a decoder that reenters seek() from getstate could free it and leave tell() reading freed memory. Own the reference across those calls, matching the sibling textiowrapper_read_chunk. (cherry picked from commit fa0ec86)
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Manual backport of #153540 to 3.13: the tests for
_io.TextIOWrapperare inLib/test/test_io.pythere, not in theLib/test/test_iopackage.