8000 [3.13] gh-116810: fix memory leak in ssl module (GH-123249) (#124800) · python/cpython@f5f1d45 · GitHub
[go: up one dir, main page]
Skip to content

Commit f5f1d45

Browse files
miss-islingtonjeffvanvoorstblurb-it[bot]ZeroIntensitygpshead
authored
[3.13] gh-116810: fix memory leak in ssl module (GH-123249) (#124800)
gh-116810: fix memory leak in ssl module (GH-123249) Resolve a memory leak introduced in CPython 3.10's :mod:`ssl` when the :attr:`ssl.SSLSocket.session` property was accessed. Speeds up read and write access to said property by no longer unnecessarily cloning session objects via serialization. (cherry picked from commit 7e7223e) Co-authored-by: Jeffrey R. Van Voorst <jeff.vanvoorst@gmail.com> Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com> Co-authored-by: Peter Bierma <zintensitydev@gmail.com> Co-authored-by: Gregory P. Smith <greg@krypto.org> Co-authored-by: Antoine Pitrou <antoine@python.org>
1 parent a93716f commit f5f1d45

File tree

2 files changed

+17
-63
lines changed

2 files changed

+17
-63
lines changed

‎Misc/NEWS.d/next/Library/2024-08-23-15-49-10.gh-issue-116810.QLBUU8.rst

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,4 @@
1+
Resolve a memory leak introduced in CPython 3.10's :mod:`ssl` when the
2+
:attr:`ssl.SSLSocket.session` property was accessed. Speeds up read and
3+
write access to said property by no longer unnecessarily cloning session
4+
objects via serialization.

‎Modules/_ssl.c

Lines changed: 13 additions & 63 deletions
Original file line numberDiff line numberDiff line change
@@ -2245,6 +2245,17 @@ PySSL_dealloc(PySSLSocket *self)
22452245
PyTypeObject *tp = Py_TYPE(self);
22462246
PyObject_GC_UnTrack(self);
22472247
if (self->ssl) {
2248+
// If we free the SSL socket object without having called SSL_shutdown,
2249+
// OpenSSL will invalidate the linked SSL session object. While this
2250+
// behavior is strictly RFC-compliant, it makes session reuse less
2251+
// likely and it would also break compatibility with older stdlib
2252+
// versions (which used an ugly workaround of duplicating the
2253+
// SSL_SESSION object).
2254+
// Therefore, we ensure the socket is marked as shutdown in any case.
2255+
//
2256+
// See elaborate explanation at
2257+
// https://github.com/python/cpython/pull/123249#discussion_r1766164530
2258+
SSL_set_shutdown(self->ssl, SSL_SENT_SHUTDOWN | SSL_get_shutdown(self->ssl));
22482259
SSL_free(self->ssl);
22492260
}
22502261
Py_XDECREF(self->Socket);
@@ -2789,64 +2800,13 @@ _ssl__SSLSocket_verify_client_post_handshake_impl(PySSLSocket *self)
27892800
#endif
27902801
}
27912802

2792-
static SSL_SESSION*
2793-
_ssl_session_dup(SSL_SESSION *session) {
2794-
SSL_SESSION *newsession = NULL;
2795-
int slen;
2796-
unsigned char *senc = NULL, *p;
2797-
const unsigned char *const_p;
2798-
2799-
if (session == NULL) {
2800-
PyErr_SetString(PyExc_ValueError, "Invalid session");
2801-
goto error;
2802-
}
2803-
2804-
/* get length */
2805-
slen = i2d_SSL_SESSION(session, NULL);
2806-
if (slen == 0 || slen > 0xFF00) {
2807-
PyErr_SetString(PyExc_ValueError, "i2d() failed");
2808-
goto error;
2809-
}
2810-
if ((senc = PyMem_Malloc(slen)) == NULL) {
2811-
PyErr_NoMemory();
2812-
goto error;
2813-
}
2814-
p = senc;
2815-
if (!i2d_SSL_SESSION(session, &p)) {
2816-
PyErr_SetString(PyExc_ValueError, "i2d() failed");
2817-
goto error;
2818-
}
2819-
const_p = senc;
2820-
newsession = d2i_SSL_SESSION(NULL, &const_p, slen);
2821-
if (newsession == NULL) {
2822-
PyErr_SetString(PyExc_ValueError, "d2i() failed");
2823-
goto error;
2824-
}
2825-
PyMem_Free(senc);
2826-
return newsession;
2827-
error:
2828-
if (senc != NULL) {
2829-
PyMem_Free(senc);
2830-
}
2831-
return NULL;
2832-
}
2833-
28342803
static PyObject *
28352804
PySSL_get_session(PySSLSocket *self, void *closure) {
28362805
/* get_session can return sessions from a server-side connection,
28372806
* it does not check for handshake done or client socket. */
28382807
PySSLSession *pysess;
28392808
SSL_SESSION *session;
28402809

2841-
/* duplicate session as workaround for session bug in OpenSSL 1.1.0,
2842-
* https://github.com/openssl/openssl/issues/1550 */
2843-
session = SSL_get0_session(self->ssl); /* borrowed reference */
2844-
if (session == NULL) {
2845-
Py_RETURN_NONE;
2846-
}
2847-
if ((session = _ssl_session_dup(session)) == NULL) {
2848-
return NULL;
2849-
}
28502810
session = SSL_get1_session(self->ssl);
28512811
if (session == NULL) {
28522812
Py_RETURN_NONE;
@@ -2865,11 +2825,8 @@ PySSL_get_session(PySSLSocket *self, void *closure) {
28652825
}
28662826

28672827
static int PySSL_set_session(PySSLSocket *self, PyObject *value,
2868-
void *closure)
2869-
{
2828+
void *closure) {
28702829
PySSLSession *pysess;
2871-
SSL_SESSION *session;
2872-
int result;
28732830

28742831
if (!Py_IS_TYPE(value, get_state_sock(self)->PySSLSession_Type)) {
28752832
PyErr_SetString(PyExc_TypeError, "Value is not a SSLSession.");
@@ -2892,14 +2849,7 @@ static int PySSL_set_session(PySSLSocket *self, PyObject *value,
28922849
"Cannot set session after handshake.");
28932850
return -1;
28942851
}
2895-
/* duplicate session */
2896-
if ((session = _ssl_session_dup(pysess->session)) == NULL) {
2897-
return -1;
2898-
}
2899-
result = SSL_set_session(self->ssl, session);
2900-
/* free duplicate, SSL_set_session() bumps ref count */
2901-
SSL_SESSION_free(session);
2902-
if (result == 0) {
2852+
if (SSL_set_session(self->ssl, pysess->session) == 0) {
29032853
_setSSLError(get_state_sock(self), NULL, 0, __FILE__, __LINE__);
29042854
return -1;
29052855
}

0 commit comments

Comments
 (0)
0