Bug 1465135
| Summary: | sssd_be dereferences NULL pointer server->common and crashes with assertion error | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Orion Poplawski <orion> |
| Component: | sssd | Assignee: | Sumit Bose <sbose> |
| Status: | CLOSED MIGRATED | QA Contact: | sssd-qe <sssd-qe> |
| Severity: | high | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.3 | CC: | aboscatt, frenaud, grajaiya, lslebodn, mkosek, mzidek, pbrezina, pkettman, qpham, tscherf |
| Target Milestone: | rc | Keywords: | MigratedToJIRA, Reopened, Triaged |
| Target Release: | --- | Flags: | pm-rhel:
mirror+
|
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2023-09-19 00:35:37 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In function ipa_resolve_callback, we have server->common == NULL. This should not be the case and is most likely a bug in SSSD. But I do not know how this could happen. There is nothing suspicious in the provided part of the logs (with the exception of the debug messages generated as a result of the fact that the server->common is NULL). I am not sure if we can fix this without reproducer. (In reply to Michal Zidek from comment #3) > In function ipa_resolve_callback, we have server->common == NULL. This > should not be the case and is most likely a bug in SSSD. > > But I do not know how this could happen. There is nothing suspicious in the > provided part of the logs (with the exception of the debug messages > generated as a result of the fact that the server->common is NULL). > > I am not sure if we can fix this without reproducer. Yes, I'm not sure either and I think it would be best to just plug the hole by checking for server->common validity. Upstream ticket: https://pagure.io/SSSD/sssd/issue/3487 Hi, maybe there is a misunderstanding here. I do not think we can plug the code with checks for NULL to avoid the assertion error. Let me describe the situation a little bit better. The NULL pointer that I talked about is the only sign that I can follow in the logs that indicates error in the code, but it is not NULL dereference that caused the crash (the code is guarded here). What happened is that a destructor that we set to free ldap connection calls ldap_unbind_ext and inside this function is an assert that we fail. I think the root cause is the same as the NULL pointer in the server->common, but I do not know how we could plug this. I looked in the public api, if there is a way to do the same check that is made by the assert before we call ldap_unbind_ext, but found no suitable function (we could skip the call if we know it is going to fail assert). I was thinking about creating some sort of flag "something_bad_happened", when we detect the NULL pointer in server->common and then skip the call in the destructor (the call for ldap_unbind_ext that fails with assertion), but that is a really ugly hack and on top of that, we have no way to actually verify that it would work (we do not have reproducer). So again, I do not think we can do anything with this without a reproducer or more information about what happened. I checked how we deal setting the LDAP handle when unbinding and at least in sdap_handle_release() we do set the handle to NULL right after unbinding, so I also don't have a good idea how to fix this, sorry :-( I guess this bugzilla could then be closed as INSUFFICIENT_INFO and we could keep the upstream patch around in "Patches Welcome" just to keep the knowledge about the problem around.. (In reply to Jakub Hrozek from comment #8) > I checked how we deal setting the LDAP handle when unbinding and at least in > sdap_handle_release() we do set the handle to NULL right after unbinding, so > I also don't have a good idea how to fix this, sorry :-( > > I guess this bugzilla could then be closed as INSUFFICIENT_INFO and we could > keep the upstream patch around in "Patches Welcome" just to keep the > knowledge about the problem around.. +1 Going to do it now. Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug. This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there. Due to differences in account names between systems, some fields were not replicated. Be sure to add yourself to Jira issue's "Watchers" field to continue receiving updates and add others to the "Need Info From" field to continue requesting information. To find the migrated issue, look in the "Links" section for a direct link to the new issue location. The issue key will have an icon of 2 footprints next to it, and begin with "RHEL-" followed by an integer. You can also find this issue by visiting https://issues.redhat.com/issues/?jql= and searching the "Bugzilla Bug" field for this BZ's number, e.g. a search like: "Bugzilla Bug" = 1234567 In the event you have trouble locating or viewing this issue, you can file an issue by sending mail to rh-issues. You can also visit https://access.redhat.com/articles/7032570 for general account information. |
Description of problem: Core was generated by `/usr/libexec/sssd/sssd_be --domain nwra.com --uid 0 --gid 0 --debug-to-files'. Program terminated with signal 11, Segmentation fault. #0 ldap_unbind_ext (ld=0x1, sctrls=0x0, cctrls=0x0) at unbind.c:46 46 assert( LDAP_VALID( ld ) ); (gdb) up #1 0x00007f0ad4dd9ba4 in sdap_handle_release (sh=0x7f0adec05e70) at src/providers/ldap/sdap_async.c:110 110 ldap_unbind_ext(sh->ldap, NULL, NULL); (gdb) print sh->ldap $1 = (LDAP *) 0x1 (gdb) print *sh $2 = {ldap = 0x1, connected = false, expire_time = 0, page_size = 1000, disable_deref = false, sdap_fd_events = 0x0, supported_saslmechs = {num_vals = 0, vals = 0x0}, supported_controls = { num_vals = 0, vals = 0x0}, supported_extensions = {num_vals = 0, vals = 0x0}, ops = 0x0, destructor_lock = true, release_memory = false} (gdb) bt #0 ldap_unbind_ext (ld=0x1, sctrls=0x0, cctrls=0x0) at unbind.c:46 #1 0x00007f0ad4dd9ba4 in sdap_handle_release (sh=0x7f0adec05e70) at src/providers/ldap/sdap_async.c:110 #2 sdap_handle_destructor (mem=<optimized out>) at src/providers/ldap/sdap_async.c:79 #3 0x00007f0ada46d447 in _talloc_free_internal () from /lib64/libtalloc.so.2 #4 0x00007f0ada466b63 in _talloc_free () from /lib64/libtalloc.so.2 #5 0x00007f0ada679680 in tevent_req_received (req=0x7f0adec08010) at ../tevent_req.c:247 #6 0x00007f0ada6796b9 in tevent_req_destructor (req=<optimized out>) at ../tevent_req.c:99 #7 0x00007f0ada466e80 in _talloc_free () from /lib64/libtalloc.so.2 #8 0x00007f0ad4dfc235 in sdap_cli_connect_done (subreq=0x7f0adec08010) at src/providers/ldap/sdap_async_connection.c:1568 #9 0x00007f0ada679512 in _tevent_req_error (req=req@entry=0x7f0adec08010, error=error@entry=111, location=location@entry=0x7f0ad4e2fee0 "src/providers/ldap/sdap_async_connection.c:158") at ../tevent_req.c:167 #10 0x00007f0ad4df7eb4 in sdap_sys_connect_done (subreq=0x0) at src/providers/ldap/sdap_async_connection.c:158 #11 0x00007f0ada679512 in _tevent_req_error (req=req@entry=0x7f0adebfd160, error=<optimized out>, location=location@entry=0x7f0ad4e3a019 "src/util/sss_ldap.c:260") at ../tevent_req.c:167 #12 0x00007f0ad4e0eac6 in sss_ldap_init_sys_connect_done (subreq=0x0) at src/util/sss_ldap.c:260 #13 0x00007f0ada679512 in _tevent_req_error (req=<optimized out>, error=<optimized out>, location=<optimized out>) at ../tevent_req.c:167 #14 0x00007f0ada679512 in _tevent_req_error (req=<optimized out>, error=<optimized out>, location=<optimized out>) at ../tevent_req.c:167 #15 0x00007f0ada67dd8b in epoll_event_loop (tvalp=0x7ffe04904f50, epoll_ev=0x7f0adeb94e70) at ../tevent_epoll.c:728 #16 epoll_event_loop_once (ev=<optimized out>, location=<optimized out>) at ../tevent_epoll.c:926 #17 0x00007f0ada67c257 in std_event_loop_once (ev=0x7f0adeb94c30, location=0x7f0ade0153ff "src/util/server.c:716") at ../tevent_standard.c:114 #18 0x00007f0ada67840d in _tevent_loop_once (ev=ev@entry=0x7f0adeb94c30, location=location@entry=0x7f0ade0153ff "src/util/server.c:716") at ../tevent.c:533 #19 0x00007f0ada6785ab in tevent_common_loop_wait (ev=0x7f0adeb94c30, location=0x7f0ade0153ff "src/util/server.c:716") at ../tevent.c:637 #20 0x00007f0ada67c1f7 in std_event_loop_wait (ev=0x7f0adeb94c30, location=0x7f0ade0153ff "src/util/server.c:716") at ../tevent_standard.c:140 #21 0x00007f0addff7f23 in server_loop (main_ctx=0x7f0adeb96080) at src/util/server.c:716 #22 0x00007f0ade874b82 in main (argc=8, argv=<optimized out>) at src/providers/data_provider_be.c:587 Version-Release number of selected component (if applicable): sssd-1.14.0-43.el7_3.14.x86_64 How reproducible: Only seen once I think. (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_set_port_status] (0x0100): Marking port 0 of server 'europa.nwra.com' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_server_common_status] (0x0100): Marking server 'ipa-boulder2.nwra.com' as 'name not resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_set_port_status] (0x0100): Marking port 0 of server 'ipa-boulder2.nwra.com' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_srv_data_status] (0x0100): Marking SRV lookup of service 'IPA' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_server_common_status] (0x0100): Marking server 'ipa2.nwra.com' as 'name not resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_set_port_status] (0x0100): Marking port 389 of server 'ipa2.nwra.com' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_srv_data_status] (0x0100): Marking SRV lookup of service 'IPA' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_server_common_status] (0x0100): Marking server 'ipa1.nwra.com' as 'name not resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_set_port_status] (0x0100): Marking port 389 of server 'ipa1.nwra.com' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_srv_data_status] (0x0100): Marking SRV lookup of service 'IPA' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_server_common_status] (0x0100): Marking server 'ipa-boulder2.nwra.com' as 'name not resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_set_port_status] (0x0100): Marking port 389 of server 'ipa-boulder2.nwra.com' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_srv_data_status] (0x0100): Marking SRV lookup of service 'IPA' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_server_common_status] (0x0100): Marking server 'europa.nwra.com' as 'name not resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_set_port_status] (0x0100): Marking port 389 of server 'europa.nwra.com' as 'neutral' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_resolve_service_send] (0x0100): Trying to resolve service 'IPA' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [resolve_srv_send] (0x0200): The status of SRV lookup is neutral (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [collapse_srv_lookup] (0x0100): Need to refresh SRV lookup for domain nwra.com (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [resolv_getsrv_send] (0x0100): Trying to resolve SRV record of '_ldap._tcp.nwra.com' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [resolv_gethostbyname_dns_query] (0x0100): Trying to resolve A record of 'ipa2.nwra.com' in DNS (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_server_common_status] (0x0100): Marking server 'ipa2.nwra.com' as 'name resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [set_srv_data_status] (0x0100): Marking SRV lookup of service 'IPA' as 'resolved' (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [be_resolve_server_process] (0x0200): Found address for server ipa2.nwra.com: [10.0.1.76] TTL 86400 (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [fo_get_server_hostent] (0x0020): Bug: Trying to get hostent from a name-less server (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [ipa_resolve_callback] (0x0020): FATAL: No hostent available for server (unknown name) (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [sssd_async_connect_done] (0x0020): connect failed [111][Connection refused]. (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [sssd_async_socket_init_done] (0x0020): sdap_async_sys_connect request failed: [111]: Connection refused. (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [sss_ldap_init_sys_connect_done] (0x0020): sssd_async_socket_init request failed: [111]: Connection refused. (Sun Jun 25 10:56:32 2017) [sssd[be[nwra.com]]] [sdap_sys_connect_done] (0x0020): sdap_async_connect_call request failed: [111]: Connection refused.