Issue 28854: FIPS mode causes dead-lock in ssl module (original) (raw)

Python's ssl module is dead-locking when OpenSSL is running in FIPS mode. I first noticed it with pip. The issue is also reproducible with Python's test suite.

$ sudo touch /etc/system-fips

$ OPENSSL_FORCE_FIPS_MODE=1 ./python -m test.regrtest -v test_ssl == CPython 2.7.12+ (2.7:adb296e4bcaa, Dec 1 2016, 21:14:20) [GCC 6.2.1 20160916 (Red Hat 6.2.1-2)] == Linux-4.8.8-200.fc24.x86_64-x86_64-with-fedora-24-Twenty_Four little-endian == /home/heimes/dev/python/2.7/build/test_python_29991 Testing with flags: sys.flags(debug=0, py3k_warning=0, division_warning=0, division_new=0, inspect=0, interactive=0, optimize=0, dont_write_bytecode=0, no_user_site=0, no_site=0, ignore_environment=0, tabcheck=0, verbose=0, unicode=0, bytes_warning=0, hash_randomization=0) [1/1] test_ssl test_ssl: testing with 'OpenSSL 1.0.2j-fips 26 Sep 2016' (1, 0, 2, 10, 15) under Linux ('Fedora', '24', 'Twenty Four') HAS_SNI = True OP_ALL = 0x800003ff OP_NO_TLSv1_1 = 0x10000000 test__create_stdlib_context (test.test_ssl.ContextTests) ... ok test__https_verify_certificates (test.test_ssl.ContextTests) ... ok test__https_verify_envvar (test.test_ssl.ContextTests) ... ok test_cert_store_stats (test.test_ssl.ContextTests) ... ok test_check_hostname (test.test_ssl.ContextTests) ... ok test_ciphers (test.test_ssl.ContextTests) ... ok test_constructor (test.test_ssl.ContextTests) ... ERROR test_create_default_context (test.test_ssl.ContextTests) ... ok test_get_ca_certs (test.test_ssl.ContextTests) ... ok test_load_cert_chain (test.test_ssl.ContextTests) ... ERROR test_load_default_certs (test.test_ssl.ContextTests) ... ok test_load_default_certs_env (test.test_ssl.ContextTests) ... ok test_load_default_certs_env_windows (test.test_ssl.ContextTests) ... skipped 'Windows specific' test_load_dh_params (test.test_ssl.ContextTests) ... ok test_load_verify_cadata (test.test_ssl.ContextTests) ... ok test_load_verify_locations (test.test_ssl.ContextTests) ... ok test_options (test.test_ssl.ContextTests) ... ok test_protocol (test.test_ssl.ContextTests) ... ERROR test_session_stats (test.test_ssl.ContextTests) ... ERROR test_set_default_verify_paths (test.test_ssl.ContextTests) ... ok test_set_ecdh_curve (test.test_ssl.ContextTests) ...

(gdb) bt #0 0x00007f0d9f8470c7 in do_futex_wait.constprop () from /lib64/libpthread.so.0 #1 0x00007f0d9f847174 in __new_sem_wait_slow.constprop.0 () from /lib64/libpthread.so.0 #2 0x00007f0d9f84721a in sem_wait@@GLIBC_2.2.5 () from /lib64/libpthread.so.0 #3 0x000000000051e013 in PyThread_acquire_lock (lock=0x27433a0, waitflag=1) at Python/thread_pthread.h:324 #4 0x00007f0d937b0dce in _ssl_thread_locking_function (mode=5, n=18, file=0x7f0d96e417ac "fips_drbg_rand.c", line=124) at /home/heimes/dev/python/2.7/Modules/_ssl.c:4000 #5 0x00007f0d96df1d7e in fips_drbg_status () from /lib64/libcrypto.so.10 #6 0x00007f0d96d75b0e in drbg_rand_add () from /lib64/libcrypto.so.10 #7 0x00007f0d96d76645 in RAND_poll () from /lib64/libcrypto.so.10 #8 0x00007f0d96d75237 in ssleay_rand_bytes () from /lib64/libcrypto.so.10 #9 0x00007f0d96d75c33 in drbg_get_entropy () from /lib64/libcrypto.so.10 #10 0x00007f0d96df10c8 in fips_get_entropy () from /lib64/libcrypto.so.10 #11 0x00007f0d96df1226 in drbg_reseed () from /lib64/libcrypto.so.10 #12 0x00007f0d96d75bb8 in drbg_rand_seed () from /lib64/libcrypto.so.10 #13 0x00007f0d96d5da84 in ECDSA_sign_ex () from /lib64/libcrypto.so.10 #14 0x00007f0d96d5db00 in ECDSA_sign () from /lib64/libcrypto.so.10 #15 0x00007f0d96d3bc10 in pkey_ec_sign () from /lib64/libcrypto.so.10 #16 0x00007f0d96d81359 in EVP_SignFinal () from /lib64/libcrypto.so.10 #17 0x00007f0d96def373 in fips_pkey_signature_test () from /lib64/libcrypto.so.10 #18 0x00007f0d96d38fe0 in EC_KEY_generate_key () from /lib64/libcrypto.so.10 #19 0x00007f0d970d7d7c in ssl3_ctx_ctrl () from /lib64/libssl.so.10 #20 0x00007f0d937af934 in set_ecdh_curve (self=0x7f0d92a23f78, name='prime256v1') at /home/heimes/dev/python/2.7/Modules/_ssl.c:3110 #21 0x00000000004d8acc in call_function (pp_stack=0x7ffcc0334730, oparg=1) at Python/ceval.c:4340 #22 0x00000000004d37a9 in PyEval_EvalFrameEx ( f=Frame 0x7f0d929bf460, for file /home/heimes/dev/python/2.7/Lib/test/test_ssl.py, line 1023, in test_set_ecdh_curve (self=<ContextTests(_resultForDoCleanups=<TextTestResult(_original_stdout=<file at remote 0x7f0d9fc281c0>, dots=False, skipped=[(<ContextTests(_resultForDoCleanups=<...>, _type_equality_funcs={<type at remote 0x7fae40>: 'assertMultiLineEqual', <type at remote 0x7f4cc0>: 'assertTupleEqual', <type at remote 0x7f0ee0>: 'assertSetEqual', <type at remote 0x7ebf80>: 'assertListEqual', <type at remote 0x7edd80>: 'assertDictEqual', <type at remote 0x7f09e0>: 'assertSetEqual'}, _testMethodDoc=None, _testMethodName='test_load_default_certs_env_windows', _cleanups=[]) at remote 0x7f0d92a80ae0>, 'Windows specific')], _mirrorOutput=False, stream=<_WritelnDecorator(stream=<file at remote 0x7f0d9fc281c0>) at remote 0x7f0d93747450>, testsRun=21, buffer=False, _original_stderr=<file at remote 0x7f0d9fc28280>, showAll=True, _stdout_buffer=None, _stderr_buffer=None, _moduleSetUpFailed=False, expectedFailures=[], er...(truncated), throwflag=0) at Python/ceval.c:2989

Python 3's test suite is dead locking in a different test:

#0 0x00007f2be93dc0c7 in do_futex_wait.constprop () from /lib64/libpthread.so.0 #1 0x00007f2be93dc174 in __new_sem_wait_slow.constprop.0 () from /lib64/libpthread.so.0 #2 0x00007f2be93dc21a in sem_wait@@GLIBC_2.2.5 () from /lib64/libpthread.so.0 #3 0x0000000000433e5c in PyThread_acquire_lock_timed (lock=0x17c0b40, microseconds=-1, intr_flag=intr_flag@entry=0) at Python/thread_pthread.h:352 #4 0x0000000000433f5e in PyThread_acquire_lock (lock=, waitflag=waitflag@entry=1) at Python/thread_pthread.h:556 #5 0x00007f2be0870945 in _ssl_thread_locking_function (mode=, n=, file=, line=) at /home/heimes/dev/python/cpython/Modules/_ssl.c:5069 #6 0x00007f2be02f4d7e in fips_drbg_status () from /lib64/libcrypto.so.10 #7 0x00007f2be0278b0e in drbg_rand_add () from /lib64/libcrypto.so.10 #8 0x00007f2be0279645 in RAND_poll () from /lib64/libcrypto.so.10 #9 0x00007f2be0278237 in ssleay_rand_bytes () from /lib64/libcrypto.so.10 #10 0x00007f2be0278c33 in drbg_get_entropy () from /lib64/libcrypto.so.10 #11 0x00007f2be02f40c8 in fips_get_entropy () from /lib64/libcrypto.so.10 #12 0x00007f2be02f4226 in drbg_reseed () from /lib64/libcrypto.so.10 #13 0x00007f2be0278b39 in drbg_rand_add () from /lib64/libcrypto.so.10 #14 0x00007f2be0868870 in _ssl_RAND_add_impl (module=module@entry=<module at remote 0x7f2be0aa1a58>, view=view@entry=0x7ffd106c1420, entropy=75) at /home/heimes/dev/python/cpython/Modules/_ssl.c:4499 #15 0x00007f2be08688f2 in _ssl_RAND_add (module=<module at remote 0x7f2be0aa1a58>, args=) at /home/heimes/dev/python/cpython/Modules/clinic/_ssl.c.h:861 #16 0x00000000004984d3 in _PyCFunction_FastCallDict ( func_obj=func_obj@entry=<built-in method RAND_add of module object at remote 0x7f2be0aa1a58>, args=args@entry=0x18d54b8, nargs=nargs@entry=2, kwargs=kwargs@entry=0x0) at Objects/methodobject.c:234 #17 0x000000000049872a in _PyCFunction_FastCallKeywords ( func=func@entry=<built-in method RAND_add of module object at remote 0x7f2be0aa1a58>, stack=stack@entry=0x18d54b8, nargs=nargs@entry=2, kwnames=kwnames@entry=0x0) at Objects/methodobject.c:295 #18 0x000000000052ad5b in call_function (pp_stack=pp_stack@entry=0x7ffd106c15d8, oparg=oparg@entry=2, kwnames=kwnames@entry=0x0) at Python/ceval.c:4735