We've very recently started seeing these AVCs on login with ThinLinc: type=AVC msg=audit(1523887506.616:384): avc: denied { dac_read_search } for pid=4290 comm="tl-session" capability=2 scontext=system_u:system_r:thinlinc_session_t:s0 tcontext=system_u:system_r:thinlinc_session_t:s0 tclass=capability permissive=0 After a lot of digging it turns out that the issue is accessing /run/user/<uid>/bus in order to start or verify the user d-bus. I'm not sure what PAM module is responsible for this, but I guess it is pam_systemd. This seems similar to the issues with unix_chkpwd that happened recently: https://bugzilla.redhat.com/show_bug.cgi?id=1451379 https://danwalsh.livejournal.com/77140.html ThinLinc has the following policy: type thinlinc_session_exec_t; corecmd_executable_file(thinlinc_session_exec_t) type thinlinc_session_t; domain_type(thinlinc_session_t) domain_entry_file(thinlinc_session_t, thinlinc_session_exec_t) auth_login_pgm_domain(thinlinc_session_t) auth_write_login_records(thinlinc_session_t) userdom_spec_domtrans_all_users(thinlinc_session_t) userdom_signal_all_users(thinlinc_session_t) allow thinlinc_session_t self:capability { kill chown dac_override fowner setgid setuid sys_resource }; allow thinlinc_session_t self:process { getcap setsched setexec setrlimit }; allow thinlinc_session_t self:fifo_file rw_fifo_file_perms; miscfiles_read_localization(thinlinc_session_t) kernel_read_kernel_sysctls(thinlinc_session_t) logging_append_all_logs(thinlinc_session_t) mcs_process_set_categories(thinlinc_session_t) mcs_killall(thinlinc_session_t) I would have hoped that auth_login_pgm_domain() would have set everything up, but perhaps another macro needs to be added?
I guess I didn't read our own policy carefully enough. I see that we were already forced to explicitly mention dac_override. And I see that upstream has added dac_read_search explicitly to a bunch of domains, so I guess that is the correct solution here?
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