bpo-42146: Fix memory leak in subprocess.Popen() in case of uid/gid overflow (GH-22966)
Fix memory leak in subprocess.Popen() in case of uid/gid overflow
Also add a test that would catch this leak with `--huntrleaks`.
Alas, the test for `extra_groups` also exposes an inconsistency
in our error reporting: we use a custom ValueError for `extra_groups`,
but propagate OverflowError for `user` and `group`.
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 9fc4434..e25474a 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -1895,6 +1895,10 @@ def test_user(self):
with self.assertRaises(ValueError):
subprocess.check_call(ZERO_RETURN_CMD, user=-1)
+ with self.assertRaises(OverflowError):
+ subprocess.check_call(ZERO_RETURN_CMD,
+ cwd=os.curdir, env=os.environ, user=2**64)
+
if pwd is None and name_uid is not None:
with self.assertRaises(ValueError):
subprocess.check_call(ZERO_RETURN_CMD, user=name_uid)
@@ -1938,6 +1942,10 @@ def test_group(self):
with self.assertRaises(ValueError):
subprocess.check_call(ZERO_RETURN_CMD, group=-1)
+ with self.assertRaises(OverflowError):
+ subprocess.check_call(ZERO_RETURN_CMD,
+ cwd=os.curdir, env=os.environ, group=2**64)
+
if grp is None:
with self.assertRaises(ValueError):
subprocess.check_call(ZERO_RETURN_CMD, group=name_group)
@@ -1986,6 +1994,11 @@ def test_extra_groups(self):
with self.assertRaises(ValueError):
subprocess.check_call(ZERO_RETURN_CMD, extra_groups=[-1])
+ with self.assertRaises(ValueError):
+ subprocess.check_call(ZERO_RETURN_CMD,
+ cwd=os.curdir, env=os.environ,
+ extra_groups=[2**64])
+
if grp is None:
with self.assertRaises(ValueError):
subprocess.check_call(ZERO_RETURN_CMD,
diff --git a/Misc/NEWS.d/next/Library/2020-10-25-19-25-02.bpo-42146.6A8uvS.rst b/Misc/NEWS.d/next/Library/2020-10-25-19-25-02.bpo-42146.6A8uvS.rst
new file mode 100644
index 0000000..0418098
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-10-25-19-25-02.bpo-42146.6A8uvS.rst
@@ -0,0 +1,2 @@
+Fix memory leak in :func:`subprocess.Popen` in case an uid (gid) specified in
+`user` (`group`, `extra_groups`) overflows `uid_t` (`gid_t`).
diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index 8baea31..5e5fbb2 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -772,7 +772,7 @@ subprocess_fork_exec(PyObject* self, PyObject *args)
uid_t uid;
gid_t gid, *groups = NULL;
int child_umask;
- PyObject *cwd_obj, *cwd_obj2;
+ PyObject *cwd_obj, *cwd_obj2 = NULL;
const char *cwd;
pid_t pid;
int need_to_reenable_gc = 0;
@@ -894,7 +894,6 @@ subprocess_fork_exec(PyObject* self, PyObject *args)
cwd = PyBytes_AsString(cwd_obj2);
} else {
cwd = NULL;
- cwd_obj2 = NULL;
}
if (groups_list != Py_None) {
@@ -1080,6 +1079,7 @@ subprocess_fork_exec(PyObject* self, PyObject *args)
return PyLong_FromPid(pid);
cleanup:
+ Py_XDECREF(cwd_obj2);
if (envp)
_Py_FreeCharPArray(envp);
if (argv)