gh-149449: Fix use-after-free in _PyUnicode_GetNameCAPI#150323
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eendebakpt wants to merge 1 commit into
Open
gh-149449: Fix use-after-free in _PyUnicode_GetNameCAPI#150323eendebakpt wants to merge 1 commit into
eendebakpt wants to merge 1 commit into
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The cache stored the raw struct pointer extracted from
unicodedata's _ucnhash_CAPI capsule without keeping a
reference to the owning capsule. Dropping the module from
sys.modules and running gc.collect() then freed the struct
while \N{...} decoding and the namereplace codec handler
were still using it. Hold a strong reference to the
capsule on the interpreter state and Py_CLEAR it in
_PyUnicode_Fini.
| return ucnhash_capi; | ||
| } | ||
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| // The pointer we cache lives inside a PyCapsule owned by the |
Contributor
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The comments are too verbose, it can be as simple as like "keep ref to capsule alive so that capsule pointer remains valid"
Contributor
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I think the simpler alternative to this is to just statically allocate |
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The cache stored the raw struct pointer extracted from unicodedata's _ucnhash_CAPI capsule without keeping a reference to the owning capsule. Dropping the module from sys.modules and running gc.collect() then freed the struct while \N{...} decoding and the namereplace codec handler were still using it. Hold a strong reference to the capsule on the interpreter state and Py_CLEAR it in _PyUnicode_Fini.
This needs backports I think, as it also affects python versions 3.10 to 3.15.
Claude was used to construct a PR.