Possible NULL dereference in `getpath_joinpath()`

[dTenebrae]

Bug report

Bug description:

    wchar_t **parts = (wchar_t **)PyMem_Malloc(n * sizeof(wchar_t *));
    memset(parts, 0, n * sizeof(wchar_t *));

The return value of PyMem_Malloc not checked for NULL and dereferenced after it in memset()

Found by Linux Verification Center (portal.linuxtesting.ru) with SVACE.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-115136: Fix possible NULL deref in getpath_joinpath() #115137
• [3.12] gh-115136: Fix possible NULL deref in getpath_joinpath() (GH-115137) #115157
• [3.11] gh-115136: Fix possible NULL deref in getpath_joinpath() (GH-115137) #115158

[hugovk]

Closing as the PR has been merged and backported. Thanks!