[Bug 1983100] Re: dotnet build intermittently crashes with segfault on Ubuntu 18.04

Wed May 3 16:27:00 UTC 2023

This updated debdiff (openssl-atexit-v2.debdiff) includes the DEP-3
headers, cleans up the patch names by prepending lp1983100- to each
patch, and is rebased on the latest release in bionic-security.

** Description changed:

  [Impact]

  Bionic's OpenSSL 1.1.1 package
  (https://launchpad.net/ubuntu/bionic/+source/openssl) is the only
  version of openssl 1.1.1 on any distro that we've encountered that does
  not have support for the OPENSSL_NO_ATEXIT functionality from 1.1.1b
  (openssl/openssl at c2b3db2).

  The threading model in .NET has the possibility that background threads
  are still running when exit() is called, which can cause SIGSEGV if a
  background thread interacts with OpenSSL after/while it has unloaded.
  For that reason, we always initialize OpenSSL 1.1.1 with the
  OPENSSL_NO_ATEXIT flag (which, of all the distros we run on only has no
  effect on Bionic).

  We feel that the stability of applications on Ubuntu 18.04 would be
  improved if the functionality of OPENSSL_NO_ATEXIT was merged into the
  bionic openssl 1.1.1 package, even if the constant isn't published into
  the header for the dev package.

  Context:
  https://github.com/dotnet/runtime/issues/48411#issuecomment-1178405101

  [Test Plan]

  The described behavior can be reproduced by passing the
  OPENSSL_NO_ATEXIT to the OPENSSL_init_ssl() call. The application will
  terminate with a SEGFAULT. More concretely, a minimal reproducer is:

  #include <stdio.h>
  #include <openssl/err.h>
  #include <openssl/ssl.h>

  #ifndef OPENSSL_INIT_NO_ATEXIT
  #define OPENSSL_INIT_NO_ATEXIT 0x00080000L
  #endif

  static void print_error_string()
  {
      printf("print_error_string:\n");
      printf("ERR_reason_error_string(0) => %s\n", ERR_reason_error_string(0));
  }

  int main(int argc, char* argv[])
  {
      // register this handler first, so it runs last.
      atexit(print_error_string);

      OPENSSL_init_ssl(
              OPENSSL_INIT_ADD_ALL_CIPHERS |
              OPENSSL_INIT_ADD_ALL_DIGESTS |
              OPENSSL_INIT_LOAD_CONFIG |
              OPENSSL_INIT_NO_ATEXIT |
              OPENSSL_INIT_LOAD_CRYPTO_STRINGS |
              OPENSSL_INIT_LOAD_SSL_STRINGS,
          NULL);

      print_error_string();

      return 0;
  }

  Building

  $ sudo apt install libssl-dev
  $ gcc test.c -lssl -lcrypto
  $ ./a.out
  print_error_string:
  ERR_reason_error_string(0) => (null)
  print_error_string:
  Segmentation fault (core dumped)

+ [Other Info]
+ All of these patches are included in upstream release 1.1.1b
+ - lp1983100-0001-Fix-shlibloadtest-to-properly-execute-the-dso_ref-te.patch
+   Fixes the shlibloadtest that was updated as part of #0005
+   
+ - lp1983100-0002-Implement-OPENSSL_INIT_NO_ATEXIT.patch
+   Patch adds the OPENSSL_INIT_NO_ATEXIT option
+ 
+ - lp1983100-0003-Don-t-link-shlibloadtest-against-libcrypto.patch
+   Additional fixes for shlibloadtest
+ 
+ - lp1983100-0004-Fix-rpath-related-Linux-test_shlibload-failure.patch
+   Additional fixes for shlibloadtest
+ 
+ - lp1983100-0005-Test-atexit-handlers.patch
+   Adds test for OPENSSL_INIT_NO_ATEXIT option and updates the shlibloadtest
+ 
+ - lp1983100-0006-Introduce-a-no-pinshared-option.patch
+   This patch includes tests to ensure that if OPENSSL_INIT_NO_ATEXIT is not defined then the atexit() handler is run
+ 
+ - lp1983100-0007-Support-_onexit-in-preference-to-atexit-on-Windows.patch
+   This patch ensures that atexit() is only called when on non-Windows systems as Windows uses _onexit() during library unloading
+ 
+ All seven patches are required to ensure the correct logic and operation
+ of the OPENSSL_INIT_NO_ATEXIT option.
+ 
  [Where problems could occur]

  The patches adds an option to the OPENSSL_init_crypto() function to
  disable the default behavior of calling of a cleanup function on
  application exit. The patch also includes a few bug fixes around various
  initializations that were supposed to happen once when running threaded
  but were not.

  These changes have the potential for regressions and it is conceivable
  that they lead to incorrect behavior. However, I have also backported
  and included all new testing functions in the hope that the changed
  behavior will get appropriate testing.

** Patch added: "openssl-atexit-v2.debdiff"
   https://bugs.launchpad.net/ubuntu/bionic/+source/openssl/+bug/1983100/+attachment/5670692/+files/openssl-atexit-v2.debdiff

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https://bugs.launchpad.net/bugs/1983100

Title:
  dotnet build intermittently crashes with segfault on Ubuntu 18.04

Status in openssl package in Ubuntu:
  Fix Released
Status in openssl source package in Bionic:
  Incomplete

Bug description:
  [Impact]

  Bionic's OpenSSL 1.1.1 package
  (https://launchpad.net/ubuntu/bionic/+source/openssl) is the only
  version of openssl 1.1.1 on any distro that we've encountered that
  does not have support for the OPENSSL_NO_ATEXIT functionality from
  1.1.1b (openssl/openssl at c2b3db2).

  The threading model in .NET has the possibility that background
  threads are still running when exit() is called, which can cause
  SIGSEGV if a background thread interacts with OpenSSL after/while it
  has unloaded. For that reason, we always initialize OpenSSL 1.1.1 with
  the OPENSSL_NO_ATEXIT flag (which, of all the distros we run on only
  has no effect on Bionic).

  We feel that the stability of applications on Ubuntu 18.04 would be
  improved if the functionality of OPENSSL_NO_ATEXIT was merged into the
  bionic openssl 1.1.1 package, even if the constant isn't published
  into the header for the dev package.

  Context:
  https://github.com/dotnet/runtime/issues/48411#issuecomment-1178405101

  [Test Plan]

  The described behavior can be reproduced by passing the
  OPENSSL_NO_ATEXIT to the OPENSSL_init_ssl() call. The application will
  terminate with a SEGFAULT. More concretely, a minimal reproducer is:

  #include <stdio.h>
  #include <openssl/err.h>
  #include <openssl/ssl.h>

  #ifndef OPENSSL_INIT_NO_ATEXIT
  #define OPENSSL_INIT_NO_ATEXIT 0x00080000L
  #endif

  static void print_error_string()
  {
      printf("print_error_string:\n");
      printf("ERR_reason_error_string(0) => %s\n", ERR_reason_error_string(0));
  }

  int main(int argc, char* argv[])
  {
      // register this handler first, so it runs last.
      atexit(print_error_string);

      OPENSSL_init_ssl(
              OPENSSL_INIT_ADD_ALL_CIPHERS |
              OPENSSL_INIT_ADD_ALL_DIGESTS |
              OPENSSL_INIT_LOAD_CONFIG |
              OPENSSL_INIT_NO_ATEXIT |
              OPENSSL_INIT_LOAD_CRYPTO_STRINGS |
              OPENSSL_INIT_LOAD_SSL_STRINGS,
          NULL);

      print_error_string();

      return 0;
  }

  Building

  $ sudo apt install libssl-dev
  $ gcc test.c -lssl -lcrypto
  $ ./a.out
  print_error_string:
  ERR_reason_error_string(0) => (null)
  print_error_string:
  Segmentation fault (core dumped)

  [Other Info]
  All of these patches are included in upstream release 1.1.1b
  - lp1983100-0001-Fix-shlibloadtest-to-properly-execute-the-dso_ref-te.patch
    Fixes the shlibloadtest that was updated as part of #0005

  - lp1983100-0002-Implement-OPENSSL_INIT_NO_ATEXIT.patch
    Patch adds the OPENSSL_INIT_NO_ATEXIT option

  - lp1983100-0003-Don-t-link-shlibloadtest-against-libcrypto.patch
    Additional fixes for shlibloadtest

  - lp1983100-0004-Fix-rpath-related-Linux-test_shlibload-failure.patch
    Additional fixes for shlibloadtest

  - lp1983100-0005-Test-atexit-handlers.patch
    Adds test for OPENSSL_INIT_NO_ATEXIT option and updates the shlibloadtest

  - lp1983100-0006-Introduce-a-no-pinshared-option.patch
    This patch includes tests to ensure that if OPENSSL_INIT_NO_ATEXIT is not defined then the atexit() handler is run

  - lp1983100-0007-Support-_onexit-in-preference-to-atexit-on-Windows.patch
    This patch ensures that atexit() is only called when on non-Windows systems as Windows uses _onexit() during library unloading

  All seven patches are required to ensure the correct logic and
  operation of the OPENSSL_INIT_NO_ATEXIT option.

  [Where problems could occur]

  The patches adds an option to the OPENSSL_init_crypto() function to
  disable the default behavior of calling of a cleanup function on
  application exit. The patch also includes a few bug fixes around
  various initializations that were supposed to happen once when running
  threaded but were not.

  These changes have the potential for regressions and it is conceivable
  that they lead to incorrect behavior. However, I have also backported
  and included all new testing functions in the hope that the changed
  behavior will get appropriate testing.

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