gh-149816: Fix SNI callback callable race by kiri11 · Pull Request #150018 · python/cpython

kiri11 · 2026-05-18T19:05:06Z

Problem

_servername_callback calls PyObject_CallFunctionObjArgs(sslctx->set_sni_cb, ...) using a shared field directly (cpython/Modules/_ssl.c:5188, cpython/Modules/_ssl.c:5215) without locking sslctx and without taking a strong local reference. Another thread can concurrently clear the field in _ssl__SSLContext_sni_callback_set_impl via Py_CLEAR(self->set_sni_cb) (cpython/Modules/_ssl.c:5304), whose macro writes NULL then decrefs/frees the old object (cpython/Include/refcount.h:483-490). A concrete UAF path is: load callable pointer in _servername_callback → concurrent Py_CLEAR frees callable → call dereferences stale pointer in _PyObject_VectorcallTstate (cpython/Objects/call.c:823).

Fix

Fix adds a critical section and saves a copy into sni_cb.

Additionally, we ensure the swap of the new callback is atomic, without allowing race conditions.

Testing

Tested on MacOS.

Before

% ./python.exe -m test test_ssl -m test_sni_callback_race
Raised RLIMIT_NOFILE: 256 -> 1024
Using random seed: 2655205590
0:00:00 load avg: 4.31 Run 1 test sequentially in a single process
0:00:00 load avg: 4.31 [1/1] test_ssl
==================
WARNING: ThreadSanitizer: data race (pid=68672)
  Write of size 8 at 0x000126f10588 by thread T29:
    #0 _ssl__SSLContext_sni_callback_set_impl _ssl.c:5304 (_ssl.cpython-316t-darwin.so:arm64+0xe5f0)
    #1 _ssl__SSLContext_sni_callback_set _ssl.c.h:2266 (_ssl.cpython-316t-darwin.so:arm64+0xe5f0)
    #2 _PyObject_GenericSetAttrWithDict object.c:2049 (python.exe:arm64+0x1000dd900)
    #3 pythread_wrapper thread_pthread.h:234 (python.exe:arm64+0x10026e378)

  Previous read of size 8 at 0x000126f10588 by thread T13:
    #0 _servername_callback _ssl.c:5159 (_ssl.cpython-316t-darwin.so:arm64+0xffa0)
    #1 final_server_name <null> (libssl.3.dylib:arm64+0x5c31c)
    #2 _PyEval_EvalFrameDefault generated_cases.c.h:4142 (python.exe:arm64+0x1001c5b50)
    #3 pythread_wrapper thread_pthread.h:234 (python.exe:arm64+0x10026e378)

  Thread T29 (tid=707684, running) created by main thread at:
    #0 pthread_create <null> (libclang_rt.tsan_osx_dynamic.dylib:arm64+0x31d84)
    #1 do_start_joinable_thread thread_pthread.h:281 (python.exe:arm64+0x10026d9f8)
    #2 do_start_new_thread _threadmodule.c:1919 (python.exe:arm64+0x10032782c)
    #3 thread_PyThread_start_joinable_thread _threadmodule.c:2042 (python.exe:arm64+0x100326894)
    #4 cfunction_call methodobject.c:564 (python.exe:arm64+0x1000d27b4)

  Thread T13 (tid=707668, running) created by main thread at:
    #0 pthread_create <null> (libclang_rt.tsan_osx_dynamic.dylib:arm64+0x31d84)
    #1 do_start_joinable_thread thread_pthread.h:281 (python.exe:arm64+0x10026d9f8)
    #2 do_start_new_thread _threadmodule.c:1919 (python.exe:arm64+0x10032782c)
    #3 thread_PyThread_start_joinable_thread _threadmodule.c:2042 (python.exe:arm64+0x100326894)
    #4 cfunction_call methodobject.c:564 (python.exe:arm64+0x1000d27b4)

SUMMARY: ThreadSanitizer: data race _ssl.c:5304 in _ssl__SSLContext_sni_callback_set_impl
==================
Warning -- Unraisable exception
Exception ignored in ssl servername callback while calling set SNI callback <NULL>:
Traceback (most recent call last):
  File "/Users/kignatev/PycharmProjects/cpython/Lib/ssl.py", line 963, in do_handshake
    self._sslobj.do_handshake()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
SystemError: null argument to internal routine
Fatal Python error: Segmentation fault

<Cannot show all threads while the GIL is disabled>
Stack (most recent call first):
  <invalid frame>

Current thread's C stack trace (most recent call first):
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _Py_DumpStack+0x44 [0x104db912c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at faulthandler_fatal_error+0x330 [0x104dddf98]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _ZN6__tsanL21CallUserSignalHandlerEPNS_11ThreadStateEbbiPN11__sanitizer23__sanitizer_siginfo_padEPv+0x104 [0x10570f910]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _Z10sighandleriPN11__sanitizer23__sanitizer_siginfo_padEPv+0x1a8 [0x10570fb68]
  Binary file "/usr/lib/system/libsystem_platform.dylib", at _sigtramp+0x38 [0x182e257a4]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_EvalFrameDefault+0xc71c [0x104d152e4]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_Vector+0x2d8 [0x104d076ec]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at object_vacall+0x138 [0x104babb78]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at PyObject_CallFunctionObjArgs+0x38 [0x104babce0]
  Binary file "/Users/kignatev/PycharmProjects/cpython/Modules/_ssl.cpython-316t-darwin.so", at _servername_callback+0x274 [0x10f9c01c8]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at final_server_name+0x6c [0x113db4320]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at tls_parse_all_extensions+0xa8 [0x113db3a10]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at tls_post_process_client_hello+0x560 [0x113dcf678]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at state_machine+0x59c [0x113dbe824]
  Binary file "/Users/kignatev/PycharmProjects/cpython/Modules/_ssl.cpython-316t-darwin.so", at _ssl__SSLSocket_do_handshake+0x184 [0x10f9c093c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_EvalFrameDefault+0x4f8c [0x104d0db54]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_Vector+0x2d8 [0x104d076ec]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyObject_VectorcallPrepend+0x144 [0x104bab0c8]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at context_run+0x88 [0x104d3b77c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at PyObject_Vectorcall+0x58 [0x104ba9a40]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _Py_VectorCallInstrumentation_StackRefSteal+0x12c [0x104d07d10]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_EvalFrameDefault+0x21b4 [0x104d0ad7c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_Vector+0x2d8 [0x104d076ec]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyObject_VectorcallPrepend+0x144 [0x104bab0c8]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at thread_run+0xe0 [0x104e6ff58]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at pythread_wrapper+0x1c [0x104db637c]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at __tsan_thread_start_func+0x8c [0x105709cf8]
  Binary file "/usr/lib/system/libsystem_pthread.dylib", at _pthread_start+0x88 [0x182e1bc58]
  Binary file "/usr/lib/system/libsystem_pthread.dylib", at thread_start+0x8 [0x182e16c1c]
ThreadSanitizer:DEADLYSIGNAL
==68672==ERROR: ThreadSanitizer: SEGV on unknown address 0x000000000000 (pc 0x000104d0ef10 bp 0x00017e422240 sp 0x00017e421fe0 T707674)
==68672==The signal is caused by a READ memory access.
==68672==Hint: address points to the zero page.
Warning -- Unraisable exception
Exception ignored in ssl servername callback while calling set SNI callback <NULL>:
Traceback (most recent call last):
  File "/Users/kignatev/PycharmProjects/cpython/Lib/ssl.py", line 963, in do_handshake
    self._sslobj.do_handshake()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
SystemError: null argument to internal routine
    #0 _PyEval_EvalFrameDefault generated_cases.c.h:5550 (python.exe:arm64+0x1001c6f10)
    #1 _PyEval_EvalFrame pycore_ceval.h:122 (python.exe:arm64+0x1001bf6e8)
    #2 _PyEval_Vector ceval.c:2156 (python.exe:arm64+0x1001bf6e8)
    #3 _PyObject_VectorcallTstate pycore_call.h:144 (python.exe:arm64+0x100063b74)
    #4 object_vacall call.c:823 (python.exe:arm64+0x100063b74)
    #5 PyObject_CallFunctionObjArgs call.c:977 (python.exe:arm64+0x100063cdc)
    #6 _servername_callback _ssl.c:5214 (_ssl.cpython-316t-darwin.so:arm64+0x101c4)
    #7 final_server_name <null> (libssl.3.dylib:arm64+0x5c31c)
    #8 tls_parse_all_extensions <null> (libssl.3.dylib:arm64+0x5ba0c)
    #9 tls_post_process_client_hello <null> (libssl.3.dylib:arm64+0x77674)
    #10 state_machine <null> (libssl.3.dylib:arm64+0x66820)
    #11 _ssl__SSLSocket_do_handshake_impl _ssl.c:1098 (_ssl.cpython-316t-darwin.so:arm64+0x10938)
    #12 _ssl__SSLSocket_do_handshake _ssl.c.h:30 (_ssl.cpython-316t-darwin.so:arm64+0x10938)
    #13 _PyEval_EvalFrameDefault generated_cases.c.h:4142 (python.exe:arm64+0x1001c5b50)
    #14 _PyEval_EvalFrame pycore_ceval.h:122 (python.exe:arm64+0x1001bf6e8)
    #15 _PyEval_Vector ceval.c:2156 (python.exe:arm64+0x1001bf6e8)
    #16 _PyObject_VectorcallTstate pycore_call.h:144 (python.exe:arm64+0x1000630c4)
    #17 _PyObject_VectorcallPrepend call.c:855 (python.exe:arm64+0x1000630c4)
    #18 _PyObject_VectorcallTstate pycore_call.h:144 (python.exe:arm64+0x1001f3778)
    #19 context_run context.c:727 (python.exe:arm64+0x1001f3778)
    #20 _PyObject_VectorcallTstate pycore_call.h:144 (python.exe:arm64+0x100061a3c)
    #21 PyObject_Vectorcall call.c:327 (python.exe:arm64+0x100061a3c)
    #22 _Py_VectorCallInstrumentation_StackRefSteal ceval.c:775 (python.exe:arm64+0x1001bfd0c)
    #23 _PyEval_EvalFrameDefault generated_cases.c.h:1846 (python.exe:arm64+0x1001c2d78)
    #24 _PyEval_EvalFrame pycore_ceval.h:122 (python.exe:arm64+0x1001bf6e8)
    #25 _PyEval_Vector ceval.c:2156 (python.exe:arm64+0x1001bf6e8)
    #26 _PyObject_VectorcallTstate pycore_call.h:144 (python.exe:arm64+0x1000630c4)
    #27 _PyObject_VectorcallPrepend call.c:855 (python.exe:arm64+0x1000630c4)
    #28 thread_run _threadmodule.c:388 (python.exe:arm64+0x100327f54)
    #29 pythread_wrapper thread_pthread.h:234 (python.exe:arm64+0x10026e378)
    #30 __tsan_thread_start_func <null> (libclang_rt.tsan_osx_dynamic.dylib:arm64+0x31cf4)
    #31 _pthread_start <null> (libsystem_pthread.dylib:arm64e+0x6c54)
    #32 thread_start <null> (libsystem_pthread.dylib:arm64e+0x1c18)

==68672==Register values:
 x[0] = 0x000000010e21dc88   x[1] = 0x00000001171c02e8   x[2] = 0x0000000000000000   x[3] = 0x000000017e422250
 x[4] = 0x0000000000000003   x[5] = 0x0000000000000000   x[6] = 0x0000000000000000   x[7] = 0x0000000000366b00
 x[8] = 0x0000000000000030   x[9] = 0x00000001171c0338  x[10] = 0x0000000000000001  x[11] = 0x0000000000000003
x[12] = 0x000000010505bda1  x[13] = 0x0000000000000003  x[14] = 0x0000000000000075  x[15] = 0x00000001eec259a0
x[16] = 0x0000000000000018  x[17] = 0x000000010e21dc70  x[18] = 0x0000000000000000  x[19] = 0x00000001171c0328
x[20] = 0x00000001171c0358  x[21] = 0x0000000104fd7da8  x[22] = 0x000000030e1001c0  x[23] = 0x000000030e1001c0
x[24] = 0x0000000000000000  x[25] = 0x0000000000000001  x[26] = 0x000000000000001d  x[27] = 0x00000001171c02e8
x[28] = 0x00000001240b8000     fp = 0x000000017e422240     lr = 0x0000000104d152e4     sp = 0x000000017e421fe0
ThreadSanitizer can not provide additional info.
SUMMARY: ThreadSanitizer: SEGV generated_cases.c.h:5550 in _PyEval_EvalFrameDefault
==68672==ABORTING
Fatal Python error: Aborted

<Cannot show all threads while the GIL is disabled>
Stack (most recent call first):
  <invalid frame>

Current thread's C stack trace (most recent call first):
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _Py_DumpStack+0x44 [0x104db912c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at faulthandler_fatal_error+0x330 [0x104dddf98]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _ZN6__tsanL21CallUserSignalHandlerEPNS_11ThreadStateEbbiPN11__sanitizer23__sanitizer_siginfo_padEPv+0x104 [0x10570f910]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _Z10sighandleriPN11__sanitizer23__sanitizer_siginfo_padEPv+0x1a8 [0x10570fb68]
  Binary file "/usr/lib/system/libsystem_platform.dylib", at _sigtramp+0x38 [0x182e257a4]
  Binary file "/usr/lib/system/libsystem_pthread.dylib", at pthread_kill+0x128 [0x182e1b8d8]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at wrap_pthread_kill+0x134 [0x105710278]
  Binary file "/usr/lib/system/libsystem_c.dylib", at abort+0x94 [0x182d22790]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _ZN11__sanitizer6AtexitEPFvvE+0x0 [0x1056f11b4]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _ZN11__sanitizer3DieEv+0x68 [0x1056f06e4]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _ZN11__sanitizer13SignalContextC1EPvS1_+0x0 [0x1056fd974]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _ZN6__tsanL21CallUserSignalHandlerEPNS_11ThreadStateEbbiPN11__sanitizer23__sanitizer_siginfo_padEPv+0x104 [0x10570f910]
  Binary file "/opt/homebrew/Cellar/llvm/22.1.5/lib/clang/22/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib", at _Z10sighandleriPN11__sanitizer23__sanitizer_siginfo_padEPv+0x1a8 [0x10570fb68]
  Binary file "/usr/lib/system/libsystem_platform.dylib", at _sigtramp+0x38 [0x182e257a4]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_EvalFrameDefault+0xc71c [0x104d152e4]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_Vector+0x2d8 [0x104d076ec]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at object_vacall+0x138 [0x104babb78]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at PyObject_CallFunctionObjArgs+0x38 [0x104babce0]
  Binary file "/Users/kignatev/PycharmProjects/cpython/Modules/_ssl.cpython-316t-darwin.so", at _servername_callback+0x274 [0x10f9c01c8]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at final_server_name+0x6c [0x113db4320]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at tls_parse_all_extensions+0xa8 [0x113db3a10]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at tls_post_process_client_hello+0x560 [0x113dcf678]
  Binary file "/opt/homebrew/Cellar/openssl@3/3.6.2/lib/libssl.3.dylib", at state_machine+0x59c [0x113dbe824]
  Binary file "/Users/kignatev/PycharmProjects/cpython/Modules/_ssl.cpython-316t-darwin.so", at _ssl__SSLSocket_do_handshake+0x184 [0x10f9c093c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_EvalFrameDefault+0x4f8c [0x104d0db54]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_Vector+0x2d8 [0x104d076ec]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyObject_VectorcallPrepend+0x144 [0x104bab0c8]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at context_run+0x88 [0x104d3b77c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at PyObject_Vectorcall+0x58 [0x104ba9a40]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _Py_VectorCallInstrumentation_StackRefSteal+0x12c [0x104d07d10]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_EvalFrameDefault+0x21b4 [0x104d0ad7c]
  Binary file "/Users/kignatev/PycharmProjects/cpython/python.exe", at _PyEval_Vector+0x2d8 [0x104d076ec]
  <truncated rest of calls>
zsh: abort      ./python.exe -m test test_ssl -m test_sni_callback_race

After

0:00:00 load avg: 4.18 [1/1] test_ssl passed

Using Repro:

% ./python.exe cpython-ft/repros/49.py
finding: 49 SSLContext.sni_callback replacement race
expected signal: native crash/fatal error/sanitizer use-after-free during concurrent SNI handshakes
parameters: seconds=10; Python=3.16.0a0; GIL_enabled=False; workers=28
------------------------------------------------------------------------
Completed without interpreter crash: 53271 handshakes, 0 Python-level failures, 245825 toggles.

More info

Issue: 22 free-threading race conditions #149816

python-cla-bot · 2026-05-18T19:05:11Z

All commit authors signed the Contributor License Agreement.

bedevere-app · 2026-05-18T19:05:12Z

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

bedevere-app · 2026-05-18T20:15:02Z

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

In Modules/_ssl.c

bedevere-app · 2026-05-18T22:27:26Z

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

bedevere-app · 2026-05-18T22:40:56Z

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.

encukou · 2026-05-19T00:57:50Z

+    if (!PyCallable_Check(value)) {
        SSL_CTX_set_tlsext_servername_callback(self->ctx, NULL);
-    }
-    else {
-        if (!PyCallable_Check(value)) {
-            SSL_CTX_set_tlsext_servername_callback(self->ctx, NULL);
-            PyErr_SetString(PyExc_TypeError,
-                            "not a callable object");
+        Py_CLEAR(self->set_sni_cb);
+        if (value != Py_None) {
+            PyErr_SetString(PyExc_TypeError, "not a callable object");
            return -1;
        }
-        self->set_sni_cb = Py_NewRef(value);
-        SSL_CTX_set_tlsext_servername_callback(self->ctx, _servername_callback);
+    }
+    else {
+        Py_INCREF(value);
+        PyObject *old_cb = _Py_atomic_exchange_ptr(&self->set_sni_cb, value);
+        Py_XDECREF(old_cb);
        SSL_CTX_set_tlsext_servername_arg(self->ctx, self);
+        SSL_CTX_set_tlsext_servername_callback(self->ctx, _servername_callback);


These changes look unnecessary if set_sni_cb is always accessed in a critical section.

Unfortunately just the critical section didn't help (thread sanitizer kept complaining). Probably because it's getting accessed from within ssl library itself, so we can't guard against that.

Add test_sni_callback_race

89d0b19

bedevere-app Bot added the tests Tests in the Lib/test dir label May 18, 2026

Improve test_sni_callback_race

be11d8b

Fix SNI callback callable race use-after-free

63d7bab

In Modules/_ssl.c

kiri11 changed the title ~~Add test_sni_callback_race~~ gh-149816: Fix SNI callback callable race May 18, 2026

bedevere-app Bot mentioned this pull request May 18, 2026

22 free-threading race conditions #149816

Open

22 tasks

Merge branch 'main' into ssl-rc-ft-49

806f3f1

blurb-it Bot and others added 6 commits May 18, 2026 22:45

📜🤖 Added by blurb_it.

1920fcb

Reorder imports

fb02f9d

Py_XDECREF in error case

dd20d00

Remove callback before Py_CLEAR

1548b6e

Remove FT_ATOMIC_LOAD_PTR_RELAXED

67da443

Don't allow callback == NULL

1ecc7df

kiri11 marked this pull request as ready for review May 19, 2026 00:17

kiri11 requested review from gpshead and picnixz as code owners May 19, 2026 00:17

bedevere-app Bot added the awaiting review label May 19, 2026

cmaloney added the sprint label May 19, 2026

github-project-automation Bot added this to Sprint May 19, 2026

github-project-automation Bot moved this to Todo in Sprint May 19, 2026

encukou reviewed May 19, 2026

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Uh oh!

gh-149816: Fix SNI callback callable race#150018

gh-149816: Fix SNI callback callable race#150018
kiri11 wants to merge 10 commits into
python:mainfrom
kiri11:ssl-rc-ft-49

kiri11 commented May 18, 2026 •

edited

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python-cla-bot Bot commented May 18, 2026 •

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kiri11 commented May 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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kiri11 commented May 18, 2026 •

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python-cla-bot Bot commented May 18, 2026 •

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