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gh-126316: Make grp.getgrall() thread-safe: add a mutex (#127055) · python/cpython@3c2bd66

8 files changed

lines changed

Original file line numberDiff line numberDiff line change

@@ -471,6 +471,7 @@ struct _Py_global_strings {

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STRUCT_FOR_ID(hi)

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STRUCT_FOR_ID(hook)

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STRUCT_FOR_ID(hour)

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STRUCT_FOR_ID(id)

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STRUCT_FOR_ID(ident)

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STRUCT_FOR_ID(identity_hint)

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STRUCT_FOR_ID(ignore)

Original file line numberDiff line numberDiff line change

@@ -0,0 +1,2 @@

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:mod:`grp`: Make :func:`grp.getgrall` thread-safe by adding a mutex. Patch

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by Victor Stinner.

Original file line numberDiff line numberDiff line change

@@ -1,9 +1,8 @@

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/* UNIX group file access module */

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3-

// Need limited C API version 3.13 for PyMem_RawRealloc()

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#include "pyconfig.h" // Py_GIL_DISABLED

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#ifndef Py_GIL_DISABLED

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#define Py_LIMITED_API 0x030d0000

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// Argument Clinic uses the internal C API

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#ifndef Py_BUILD_CORE_BUILTIN

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# define Py_BUILD_CORE_MODULE 1

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#endif

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#include "Python.h"

@@ -281,23 +280,33 @@ static PyObject *

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grp_getgrall_impl(PyObject *module)

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/*[clinic end generated code: output=585dad35e2e763d7 input=d7df76c825c367df]*/

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{

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PyObject *d;

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struct group *p;

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if ((d = PyList_New(0)) == NULL)

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PyObject *d = PyList_New(0);

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if (d == NULL) {

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return NULL;

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}

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static PyMutex getgrall_mutex = {0};

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PyMutex_Lock(&getgrall_mutex);

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setgrent();

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struct group *p;

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while ((p = getgrent()) != NULL) {

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// gh-126316: Don't release the mutex around mkgrent() since

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// setgrent()/endgrent() are not reentrant / thread-safe. A deadlock

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// is unlikely since mkgrent() should not be able to call arbitrary

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// Python code.

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PyObject *v = mkgrent(module, p);

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if (v == NULL || PyList_Append(d, v) != 0) {

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Py_XDECREF(v);

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Py_DECREF(d);

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endgrent();

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return NULL;

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Py_CLEAR(d);

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goto done;

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}

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Py_DECREF(v);

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}

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done:

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endgrent();

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PyMutex_Unlock(&getgrall_mutex);

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return d;

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}

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Original file line numberDiff line numberDiff line change

@@ -739,6 +739,7 @@ Modules/expat/xmlrole.c - declClose -

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Modules/expat/xmlrole.c - error -

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## other

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Modules/grpmodule.c grp_getgrall_impl getgrall_mutex -

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Modules/_io/_iomodule.c - _PyIO_Module -

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Modules/_sqlite/module.c - _sqlite3module -

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Modules/clinic/md5module.c.h _md5_md5 _keywords -