** 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@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)); + 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; + // 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 + $ ./a.out print_error_string: ERR_reason_error_string(0) => (null) print_error_string: Segmentation fault (core dumped) [Where problems could occur] - * Think about what the upload changes in the software. Imagine the change is - wrong or breaks something else: how would this show up? + 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. - * It is assumed that any SRU candidate patch is well-tested before - upload and has a low overall risk of regression, but it's important - to make the effort to think about what ''could'' happen in the - event of a regression. - - * This must '''never''' be "None" or "Low", or entirely an argument as to why - your upload is low risk. - - * This both shows the SRU team that the risks have been considered, - and provides guidance to testers in regression-testing the SRU. - - - [Other Info] - - * Anything else you think is useful to include - * Anticipate questions from users, SRU, +1 maintenance, security teams and the Technical Board - * and address these questions in advance + 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.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssl in Ubuntu. https://bugs.launchpad.net/bugs/1983100 Title: dotnet build intermittently crashes with segfault on Ubuntu 18.04 Status in openssl package in Ubuntu: New Status in openssl source package in Bionic: New 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@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) [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. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssl/+bug/1983100/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
