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gh-145301: Fix double-free in hashlib and hmac module initialization #145321

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gh-145301: Fix double-free in hashlib and hmac module initialization #145321

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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2026-02-27-19-00-26.gh-issue-145301.2Wih4b.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
:mod:`hashlib`: fix a crash when the initialization of the underlying C
extension module fails.
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2026-02-28-00-55-00.gh-issue-145301.Lk2bRl.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
:mod:`hmac`: fix a crash when the initialization of the underlying C
extension module fails.
2 changes: 1 addition & 1 deletion Modules/_hashopenssl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -268,7 +268,7 @@ py_hashentry_table_new(void) {

if (h->py_alias != NULL) {
if (_Py_hashtable_set(ht, (const void*)entry->py_alias, (void*)entry) < 0) {
PyMem_Free(entry);
/* entry is already in ht, will be freed by _Py_hashtable_destroy() */
goto error;
}
entry->refcnt++;
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23 changes: 13 additions & 10 deletions Modules/hmacmodule.c
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Expand Up @@ -1453,16 +1453,19 @@ py_hmac_hinfo_ht_new(void)
assert(value->display_name == NULL);
value->refcnt = 0;

#define Py_HMAC_HINFO_LINK(KEY) \
do { \
int rc = py_hmac_hinfo_ht_add(table, KEY, value); \
if (rc < 0) { \
PyMem_Free(value); \
goto error; \
} \
else if (rc == 1) { \
value->refcnt++; \
} \
#define Py_HMAC_HINFO_LINK(KEY) \
do { \
int rc = py_hmac_hinfo_ht_add(table, (KEY), value); \
if (rc < 0) { \
/* entry may already be in ht, freed upon exit */ \
if (value->refcnt == 0) { \
PyMem_Free(value); \
} \
goto error; \
} \
else if (rc == 1) { \
value->refcnt++; \
} \
} while (0)
Py_HMAC_HINFO_LINK(e->name);
Py_HMAC_HINFO_LINK(e->hashlib_name);
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