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gh-149931: Fix memory leaks on failed realloc #149932

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gh-149931: Fix memory leaks on failed realloc #149932

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2c0792f
Fix memory leaks on failed realloc
aisk May 17, 2026
eab61bf
Remove news entry
aisk May 17, 2026
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6 changes: 4 additions & 2 deletions Modules/_remote_debugging/frames.c
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Original file line number Diff line number Diff line change
Expand Up @@ -56,12 +56,14 @@ process_single_stack_chunk(
return -1;
}

this_chunk = PyMem_RawRealloc(this_chunk, actual_size);
if (!this_chunk) {
char *tmp = PyMem_RawRealloc(this_chunk, actual_size);
if (!tmp) {
PyMem_RawFree(this_chunk);
PyErr_NoMemory();
set_exception_cause(unwinder, PyExc_MemoryError, "Failed to reallocate stack chunk buffer");
return -1;
}
this_chunk = tmp;

if (_Py_RemoteDebug_PagedReadRemoteMemory(&unwinder->handle, chunk_addr, actual_size, this_chunk) < 0) {
PyMem_RawFree(this_chunk);
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7 changes: 4 additions & 3 deletions Modules/timemodule.c
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Original file line number Diff line number Diff line change
Expand Up @@ -820,12 +820,13 @@ time_strftime1(time_char **outbuf, size_t *bufsize,
PyErr_NoMemory();
return NULL;
}
*outbuf = (time_char *)PyMem_Realloc(*outbuf,
*bufsize*sizeof(time_char));
if (*outbuf == NULL) {
time_char *tmp = (time_char *)PyMem_Realloc(*outbuf,
*bufsize*sizeof(time_char));
if (tmp == NULL) {
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@MojoVampire MojoVampire May 18, 2026

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This is a loop, so while the caller's *outbuf might have initially been NULL, and we could have allocated on their behalf, and left them with something allocated (that is useless) even though we failed. We're only called in one place and it unconditionally frees (which is NULL friendly) eventually, so this isn't a big deal, but it feels like, if this could conceivably be called in any other way, failure should involve freeing and NULLing *outbuf.

PyErr_NoMemory();
return NULL;
}
*outbuf = tmp;
#if defined _MSC_VER && _MSC_VER >= 1400 && defined(__STDC_SECURE_LIB__)
errno = 0;
#endif
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