** Tags removed: verification-needed-xenial ** Tags added: verification-done-xenial
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openldap in Ubuntu. https://bugs.launchpad.net/bugs/1688575 Title: Segmentation fault on a slave slapd (sync replication with kerberos authentication) Status in openldap: Fix Released Status in openldap package in Ubuntu: Fix Released Status in openldap source package in Xenial: Fix Committed Bug description: [Impact] Concurrent SASL authentications could trigger a segfault. This was observed by the bug reporter during replication from a master to a slave, and can be reproduced with a test program. The fix is applied upstream, see comment #13. [Test Case] * Create a fresh xenial VM or container and login. Update the apt repositories: sudo apt update * Create a local directory and cd into it: mkdir test && cd test * Download the test attachments from this bug: Makefile, sasltest.c and testscript: wget https://bugs.launchpad.net/ubuntu/+source/openldap/+bug/1688575/+attachment/5139678/+files/Makefile https://bugs.launchpad.net/ubuntu/+source/openldap/+bug/1688575/+attachment/5139679/+files/sasltest.c https://bugs.launchpad.net/ubuntu/+source/openldap/+bug/1688575/+attachment/5139680/+files/testscript * Build with $ apt install libsasl2-dev libldap2-dev $ make * Execute the testscript with sudo once. It shall fail at the very end with a core dump: sudo sh ./testscript (...) sasltest: sasltest.c:70: bind_thread: Assertion `rc == LDAP_SUCCESS' failed. Aborted (core dumped) * Export this var: export LDAPSASL_SECPROPS=none * Run the actual test script a few more times to confirm the crasH: $ ./sasltest rc = -6 (Unknown authentication method) sasltest: sasltest.c:70: bind_thread: Assertion `rc == LDAP_SUCCESS' failed. rc = -6 (Unknown authentication method) sasltest: sasltest.c:70: bind_thread: Assertion `rc == LDAP_SUCCESS' failed. rc = -6 (Unknown authentication method) sasltest: sasltest.c:70: bind_thread: Assertion `rc == LDAP_SUCCESS' failed. Aborted (core dumped) * Install the updated packages from proposed * Run ./sasltest again. Make sure the LDAPSASL_SECPROPS var is still exported: $ echo $LDAPSASL_SECPROPS none $ ./sasltest $ This time the test completes without crashing. [Regression Potential] This is SASL authentication, and with kerberos nonetheless (in the case of the bug reporter). I suspect not many people deploy this due to its complexity. The ones that have such a setup, however, tend to know what they are doing, so if they say the problem is fixed for them, I believe it is. About this particular change, it's committed upstream and also in debian, and @rtandy was kind enough to provide a sample test script that exhibits the problem. [Other Info] Since the fix is applied upstream and in Debian, there shouldn't be additional surprises here. [Original description] I have a slapd problem on a freshly installed 16.04 machine: slapd[17107]: segfault at 1a ip 00007f3c12c79f55 sp 00007f3c03c2d080 error 4 in libsasl2.so.2.0.25[7f3c12c72000+19000] I'm using the server as Slave LDAP-Server and sync replication with kerberos authentication. The service either starts and runs successfully or it fails with segmentation fault or 100% CPU. Maybe an useful info, I'm replicating two databases. When I deactivate syncrepl for one of them (doesn't matter which one) the problem is not occuring. Linux xxx 4.4.0-75-generic #96-Ubuntu SMP Thu Apr 20 09:56:33 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux slapd 2.4.42+dfsg-2ubuntu3.1 libsasl2-2:amd64 2.1.26.dfsg1-14build1 libsasl2-modules:amd64 2.1.26.dfsg1-14build1 libsasl2-modules-gssapi-mit:amd64 2.1.26.dfsg1-14build1 GDB debug: Starting program: /usr/sbin/slapd -h "ldap:/// ldaps:/// ldapi:///" -u openldap -g openldap -f /etc/ldap/slapd.conf -d 256 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". 590c82ab @(#) $OpenLDAP: slapd (Ubuntu) (May 11 2016 16:12:05) $ buildd@lgw01-10:/build/openldap-mF7Kfq/openldap-2.4.42+dfsg/debian/build/servers/slapd 590c82ab slapd starting [New Thread 0x7f2e96b7b700 (LWP 42139)] [New Thread 0x7f2e9637a700 (LWP 42140)] [New Thread 0x7f2e95b79700 (LWP 42141)] [New Thread 0x7f2e95378700 (LWP 42142)] [New Thread 0x7f2e94b77700 (LWP 42143)] 590c82ba slap_client_connect: URI=ldap://xxx ldap_sasl_interactive_bind_s failed (-6) 590c82ba do_syncrepl: rid=132 rc -6 retrying (9 retries left) Thread 4 "slapd" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7f2e95b79700 (LWP 42141)] 0x00007f2ea53035b5 in sasl_client_add_plugin () from /usr/lib/x86_64-linux-gnu/libsasl2.so.2 (gdb) thr apply all bt Thread 6 (Thread 0x7f2e94b77700 (LWP 42143)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007f2ea59463f3 in ?? () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #2 0x00007f2ea487c6ba in start_thread (arg=0x7f2e94b77700) at pthread_create.c:333 #3 0x00007f2ea45b282d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 5 (Thread 0x7f2e95378700 (LWP 42142)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007f2ea59463f3 in ?? () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #2 0x00007f2ea487c6ba in start_thread (arg=0x7f2e95378700) at pthread_create.c:333 #3 0x00007f2ea45b282d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 4 (Thread 0x7f2e95b79700 (LWP 42141)): #0 0x00007f2ea53035b5 in sasl_client_add_plugin () from /usr/lib/x86_64-linux-gnu/libsasl2.so.2 #1 0x00007f2ea530f250 in ?? () from /usr/lib/x86_64-linux-gnu/libsasl2.so.2 #2 0x00007f2ea5303d69 in sasl_client_init () from /usr/lib/x86_64-linux-gnu/libsasl2.so.2 #3 0x00007f2ea594da6c in ldap_int_sasl_init () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #4 0x00007f2ea594db2c in ldap_int_sasl_open () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #5 0x00007f2ea594e2d4 in ldap_int_sasl_bind () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #6 0x00007f2ea5951828 in ldap_sasl_interactive_bind () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #7 0x00007f2ea5951a4e in ldap_sasl_interactive_bind_s () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #8 0x0000561fbc556db4 in slap_client_connect (ldp=0x561fbe1e9f68, sb=0x561fbe1e9d40) at ../../../../servers/slapd/config.c:2063 #9 0x0000561fbc5c699d in do_syncrep1 (si=0x561fbe1e9d10, op=0x7f2e95b787b0) at ../../../../servers/slapd/syncrepl.c:618 #10 do_syncrepl (ctx=<optimized out>, arg=0x561fbe1e5620) at ../../../../servers/slapd/syncrepl.c:1548 #11 0x00007f2ea59463a2 in ?? () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #12 0x00007f2ea487c6ba in start_thread (arg=0x7f2e95b79700) at pthread_create.c:333 #13 0x00007f2ea45b282d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 3 (Thread 0x7f2e9637a700 (LWP 42140)): ---Type <return> to continue, or q <return> to quit--- #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007f2ea59463f3 in ?? () from /usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2 #2 0x00007f2ea487c6ba in start_thread (arg=0x7f2e9637a700) at pthread_create.c:333 #3 0x00007f2ea45b282d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 2 (Thread 0x7f2e96b7b700 (LWP 42139)): #0 0x00007f2ea45b2e23 in epoll_wait () at ../sysdeps/unix/syscall-template.S:84 #1 0x0000561fbc55a8f0 in slapd_daemon_task (ptr=<optimized out>) at ../../../../servers/slapd/daemon.c:2539 #2 0x00007f2ea487c6ba in start_thread (arg=0x7f2e96b7b700) at pthread_create.c:333 #3 0x00007f2ea45b282d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 1 (Thread 0x7f2ea5d96740 (LWP 42138)): #0 0x00007f2ea487d98d in pthread_join (threadid=139838073845504, thread_return=0x0) at pthread_join.c:90 #1 0x0000561fbc55cc81 in slapd_daemon () at ../../../../servers/slapd/daemon.c:2932 #2 0x0000561fbc543bea in main (argc=11, argv=<optimized out>) at ../../../../servers/slapd/main.c:1017 (gdb) To manage notifications about this bug go to: https://bugs.launchpad.net/openldap/+bug/1688575/+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
