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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2020-05-24 14:43:02 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-05-24 14:43:02 (GMT) |
| commit | ebf650532b41f5e64a5620b8e47acc3a99555e14 (patch) | |
| tree | c287da44dc482a43d76fcceee0f3d4ea46b75f4f /Modules | |
| parent | 21a9af193c35394f560d9517e7a4b579f40b8ef7 (diff) | |
| download | cpython-ebf650532b41f5e64a5620b8e47acc3a99555e14.zip cpython-ebf650532b41f5e64a5620b8e47acc3a99555e14.tar.gz cpython-ebf650532b41f5e64a5620b8e47acc3a99555e14.tar.bz2 | |
bpo-40705: Fix use-after-free in _zoneinfo's module_free (GH-20280)
(cherry picked from commit 06a1b8915d6674e40f0dccc422ca2c06212392d8)
Co-authored-by: Ammar Askar <ammar@ammaraskar.com>
Diffstat (limited to 'Modules')
| -rw-r--r-- | Modules/_zoneinfo.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/Modules/_zoneinfo.c b/Modules/_zoneinfo.c index d7e7157..d852c76 100644 --- a/Modules/_zoneinfo.c +++ b/Modules/_zoneinfo.c @@ -2490,6 +2490,7 @@ new_weak_cache() static int initialize_caches() { + // TODO: Move to a PyModule_GetState / PEP 573 based caching system. if (TIMEDELTA_CACHE == NULL) { TIMEDELTA_CACHE = PyDict_New(); } @@ -2603,14 +2604,16 @@ module_free() xdecref_ttinfo(&NO_TTINFO); - Py_XDECREF(TIMEDELTA_CACHE); - if (!Py_REFCNT(TIMEDELTA_CACHE)) { - TIMEDELTA_CACHE = NULL; + if (TIMEDELTA_CACHE != NULL && Py_REFCNT(TIMEDELTA_CACHE) > 1) { + Py_DECREF(TIMEDELTA_CACHE); + } else { + Py_CLEAR(TIMEDELTA_CACHE); } - Py_XDECREF(ZONEINFO_WEAK_CACHE); - if (!Py_REFCNT(ZONEINFO_WEAK_CACHE)) { - ZONEINFO_WEAK_CACHE = NULL; + if (ZONEINFO_WEAK_CACHE != NULL && Py_REFCNT(ZONEINFO_WEAK_CACHE) > 1) { + Py_DECREF(ZONEINFO_WEAK_CACHE); + } else { + Py_CLEAR(ZONEINFO_WEAK_CACHE); } strong_cache_free(ZONEINFO_STRONG_CACHE); |