From c00ac578241b3213ceb79c1f32bc83ea471f02da Mon Sep 17 00:00:00 2001 From: Sam Gross Date: Tue, 11 Mar 2025 19:15:22 -0400 Subject: [PATCH] gh-131113: Fix data race in dict.popitem() (gh-131115) The clearing of the key, hash, and value need to use atomic operations to avoid a data race with concurrent read operations. --- Objects/dictobject.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/Objects/dictobject.c b/Objects/dictobject.c index d74bec775e43..254c1317e903 100644 --- a/Objects/dictobject.c +++ b/Objects/dictobject.c @@ -275,10 +275,10 @@ load_keys_nentries(PyDictObject *mp) #endif -#define STORE_KEY(ep, key) FT_ATOMIC_STORE_PTR_RELEASE(ep->me_key, key) -#define STORE_VALUE(ep, value) FT_ATOMIC_STORE_PTR_RELEASE(ep->me_value, value) +#define STORE_KEY(ep, key) FT_ATOMIC_STORE_PTR_RELEASE((ep)->me_key, key) +#define STORE_VALUE(ep, value) FT_ATOMIC_STORE_PTR_RELEASE((ep)->me_value, value) #define STORE_SPLIT_VALUE(mp, idx, value) FT_ATOMIC_STORE_PTR_RELEASE(mp->ma_values->values[idx], value) -#define STORE_HASH(ep, hash) FT_ATOMIC_STORE_SSIZE_RELAXED(ep->me_hash, hash) +#define STORE_HASH(ep, hash) FT_ATOMIC_STORE_SSIZE_RELAXED((ep)->me_hash, hash) #define STORE_KEYS_USABLE(keys, usable) FT_ATOMIC_STORE_SSIZE_RELAXED(keys->dk_usable, usable) #define STORE_KEYS_NENTRIES(keys, nentries) FT_ATOMIC_STORE_SSIZE_RELAXED(keys->dk_nentries, nentries) #define STORE_USED(mp, used) FT_ATOMIC_STORE_SSIZE_RELAXED(mp->ma_used, used) @@ -4534,8 +4534,8 @@ dict_popitem_impl(PyDictObject *self) _PyDict_NotifyEvent(interp, PyDict_EVENT_DELETED, self, key, NULL); hash = unicode_get_hash(key); value = ep0[i].me_value; - ep0[i].me_key = NULL; - ep0[i].me_value = NULL; + STORE_KEY(&ep0[i], NULL); + STORE_VALUE(&ep0[i], NULL); } else { PyDictKeyEntry *ep0 = DK_ENTRIES(self->ma_keys); @@ -4549,9 +4549,9 @@ dict_popitem_impl(PyDictObject *self) _PyDict_NotifyEvent(interp, PyDict_EVENT_DELETED, self, key, NULL); hash = ep0[i].me_hash; value = ep0[i].me_value; - ep0[i].me_key = NULL; - ep0[i].me_hash = -1; - ep0[i].me_value = NULL; + STORE_KEY(&ep0[i], NULL); + STORE_HASH(&ep0[i], -1); + STORE_VALUE(&ep0[i], NULL); } j = lookdict_index(self->ma_keys, hash, i);