Re: [PATCH ghau90 v1] sig_info: use standard template for log messages

On Monday, April 15, 2019 12:21:49 PM EDT Richard Guy Briggs wrote: > On 2019-04-15 10:58, Steve Grubb wrote: > > On Monday, April 15, 2019 9:02:36 AM EDT Richard Guy Briggs wrote: > > > Records that are triggered by an AUDIT_SIGNAL_INFO message including > > > AUDIT_DAEMON_CONFIG (HUP), AUDIT_DAEMON_ROTATE (USR1), > > > AUDIT_DAEMON_RESUME (USR2) and AUDIT_DAEMON_END (TERM) have > > > inconsistent reporting of signal info and swinging field "state". > > > > This is crusty old code that has things in it that were for migrations > > with very old kernels. It's not readily obvious because those kernel > > transitions were quite some time ago. There was also a fake > > > > > They also assume that an empty security context implies there is no > > > other useful information in the AUDIT_SIGNAL_INFO message so don't use > > > the information that is there. > > > > How are you generating the events that trigger this? If this is based on > > reading the source code, I think its because of an ancient kernel change. > > If you can generate this condition, then I'd like to replicate the > > problem on my system to see what's happening. > > I used a current audit/next kernel, compiled with AUDIT_CONFIG, but with > and without AUDIT_CONFIGSYSCALL Is this a configuration that we really want to support? :-) This really will not work as anything except for gathering AVC's or other LSM events. And I think those go to syslog anyways. I'd say that with this kernel configuration, they likely would not run auditd as there's no point in it.

> and simply signalled the audit daemon with the four signals and then ran > ausearch on the most recent messages. > > I did not generate errors, but I could have by creating a custom kernel > that returned errors upon request for AUDIT_SIGNAL_INFO. > > > > Normalize AUDIT_DAEMON_CONFIG to use the value "reconfigure" and add > > > the "state" field where missing. > > > > > > Use audit_sig_info values when available, not making assumptions about > > > their availability when the security context is absent. > > > > > > See: https://github.com/linux-audit/audit-userspace/issues/90 > > > > I had made changes to the git repo Saturday. I suspect this patch does > > not apply. I like the op value changes. That part I can go along with. > > Shall I just make that adjustment in the upstream repo and we can talk > > more about how you are creating these events? > > This patch was rebased on your patch so it is current. One thing I should mention, the audit events are created with and without the subj field because for common criteria, a DAC based system should have no notion of MAC fields. This is why we alway branch on the "ctx" variables and create the event with or without subj.

> I wanted it all in one function so that the format was consistent rather > than open coded for anything that could use the AUDIT_SIGNAL_INFO > contents. This will also help once there is also a cid (contid) to > report. OK. -Steve > > > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; > > > --- > > > > > > docs/audit_request_signal_info.3 | 2 +- > > > lib/libaudit.c | 12 +++++++++ > > > lib/libaudit.h | 1 + > > > src/auditd-reconfig.c | 9 +++---- > > > src/auditd.c | 54 > > > > > > ++++++++++++++-------------------------- 5 files changed, 36 > > > insertions(+), 42 deletions(-) > > > > > > diff --git a/docs/audit_request_signal_info.3 > > > b/docs/audit_request_signal_info.3 index 873deb58bef3..b68d7bbefeed > > > 100644 > > > --- a/docs/audit_request_signal_info.3 > > > +++ b/docs/audit_request_signal_info.3 > > > @@ -8,7 +8,7 @@ int audit_request_signal_info(int fd); > > > > > > .SH "DESCRIPTION" > > > > > > -audit_request_signal_info requests that the kernel send information > > > about > > > the sender of a signal to the audit daemon. The sinal info structure is > > > as > > > follows: +audit_request_signal_info requests that the kernel send > > > information about the sender of a signal to the audit daemon. The > > > signal > > > > > > info structure is as follows: > > > .nf > > > struct audit_sig_info { > > > > > > diff --git a/lib/libaudit.c b/lib/libaudit.c > > > index 2af017a0e520..e9c4f9cad6df 100644 > > > --- a/lib/libaudit.c > > > +++ b/lib/libaudit.c > > > @@ -674,6 +674,18 @@ int audit_request_signal_info(int fd) > > > > > > return rc; > > > > > > } > > > > > > +char *audit_format_signal_info(char *buf, int len, char *op, struct > > > audit_reply *rep, char *res) +{ > > > + snprintf(buf, len, > > > + "op=%s auid=%u pid=%d subj=%s res=%s", > > > + op, > > > + rep->signal_info->uid, > > > + rep->signal_info->pid, > > > + rep->len == 24 ? "?" : rep->signal_info->ctx, > > > + res); > > > + return buf; > > > +} > > > + > > > > > > int audit_update_watch_perms(struct audit_rule_data *rule, int perms) > > > { > > > > > > unsigned int i, done=0; > > > > > > diff --git a/lib/libaudit.h b/lib/libaudit.h > > > index ca7aa63e354e..63a5e948d00e 100644 > > > --- a/lib/libaudit.h > > > +++ b/lib/libaudit.h > > > @@ -562,6 +562,7 @@ extern int audit_setloginuid(uid_t uid); > > > > > > extern uint32_t audit_get_session(void); > > > extern int audit_detect_machine(void); > > > extern int audit_determine_machine(const char *arch); > > > > > > +extern char *audit_format_signal_info(char *buf, int len, char *op, > > > struct audit_reply *rep, char *res); > > > > > > /* Translation functions */ > > > extern int audit_name_to_field(const char *field); > > > > > > diff --git a/src/auditd-reconfig.c b/src/auditd-reconfig.c > > > index a03e29aa57ab..f5b00e6d1dc7 100644 > > > --- a/src/auditd-reconfig.c > > > +++ b/src/auditd-reconfig.c > > > @@ -115,12 +115,9 @@ static void *config_thread_main(void *arg) > > > > > > } else { > > > > > > // need to send a failed event message > > > char txt[MAX_AUDIT_MESSAGE_LENGTH]; > > > > > > - snprintf(txt, sizeof(txt), > > > - "op=reconfigure state=no-change auid=%u pid=%d subj=%s > > > > res=failed", > > > > > - e->reply.signal_info->uid, > > > - e->reply.signal_info->pid, > > > - (e->reply.len > 24) ? > > > - e->reply.signal_info->ctx : "?"); > > > + audit_format_signal_info(txt, sizeof(txt), > > > + "reconfigure state=no-change", > > > + &e->reply, "failed"); > > > > > > // FIXME: need to figure out sending this > > > //send_audit_event(AUDIT_DAEMON_CONFIG, txt); > > > free_config(&new_config); > > > > > > diff --git a/src/auditd.c b/src/auditd.c > > > index c04a1c9ce93f..5c31583a49c6 100644 > > > --- a/src/auditd.c > > > +++ b/src/auditd.c > > > @@ -131,7 +131,7 @@ static void hup_handler( struct ev_loop *loop, > > > struct > > > ev_signal *sig, int revent rc = audit_request_signal_info(fd); > > > > > > if (rc < 0) > > > > > > send_audit_event(AUDIT_DAEMON_CONFIG, > > > > > > - "op=hup-info state=request-siginfo auid=-1 pid=-1 subj=? > > > > res=failed"); > > > > > + "op=reconfigure state=no-change auid=-1 pid=-1 subj=? res=failed"); > > > > > > else > > > > > > hup_info_requested = 1; > > > > > > } > > > > > > @@ -147,7 +147,7 @@ static void user1_handler(struct ev_loop *loop, > > > struct > > > ev_signal *sig, rc = audit_request_signal_info(fd); > > > > > > if (rc < 0) > > > > > > send_audit_event(AUDIT_DAEMON_ROTATE, > > > > > > - "op=usr1-info auid=-1 pid=-1 subj=? res=failed"); > > > + "op=rotate-logs auid=-1 pid=-1 subj=? res=failed"); > > > > > > else > > > > > > usr1_info_requested = 1; > > > > > > } > > > > > > @@ -163,7 +163,7 @@ static void user2_handler( struct ev_loop *loop, > > > struct ev_signal *sig, int reve if (rc < 0) { > > > > > > resume_logging(); > > > send_audit_event(AUDIT_DAEMON_RESUME, > > > > > > - "op=resume-logging auid=-1 pid=-1 subj=? > > > > res=success"); > > > > > + "op=resume-logging auid=-1 pid=-1 subj=? res=failed"); > > > > > > } else > > > > > > usr2_info_requested = 1; > > > > > > } > > > > > > @@ -515,45 +515,33 @@ static void netlink_handler(struct ev_loop *loop, > > > struct ev_io *io, break; > > > > > > case AUDIT_SIGNAL_INFO: > > > if (hup_info_requested) { > > > > > > + char hup[MAX_AUDIT_MESSAGE_LENGTH]; > > > > > > audit_msg(LOG_DEBUG, > > > > > > "HUP detected, starting config manager"); > > > > > > reconfig_ev = cur_event; > > > if (start_config_manager(cur_event)) { > > > > > > - send_audit_event( > > > - AUDIT_DAEMON_CONFIG, > > > - "op=reconfigure state=no-change " > > > - "auid=-1 pid=-1 subj=? res=failed"); > > > + audit_format_signal_info(hup, sizeof(hup), > > > + "reconfigure > > > > state=no-change", > > > > > + &cur_event->reply, > > > + "failed"); > > > + send_audit_event(AUDIT_DAEMON_CONFIG, > > > > hup); > > > > > } > > > cur_event = NULL; > > > hup_info_requested = 0; > > > > > > } else if (usr1_info_requested) { > > > > > > char usr1[MAX_AUDIT_MESSAGE_LENGTH]; > > > > > > - if (cur_event->reply.len == 24) { > > > - snprintf(usr1, sizeof(usr1), > > > - "op=rotate-logs auid=-1 pid=-1 subj=?"); > > > - } else { > > > - snprintf(usr1, sizeof(usr1), > > > - "op=rotate-logs auid=%u pid=%d subj=%s", > > > - cur_event->reply.signal_info->uid, > > > - cur_event->reply.signal_info->pid, > > > - cur_event->reply.signal_info->ctx); > > > - } > > > + audit_format_signal_info(usr1, sizeof(usr1), > > > + "rotate-logs", > > > + &cur_event->reply, > > > + "success"); > > > > > > send_audit_event(AUDIT_DAEMON_ROTATE, usr1); > > > usr1_info_requested = 0; > > > > > > } else if (usr2_info_requested) { > > > > > > char usr2[MAX_AUDIT_MESSAGE_LENGTH]; > > > > > > - if (cur_event->reply.len == 24) { > > > - snprintf(usr2, sizeof(usr2), > > > - "op=resume-logging auid=-1 " > > > - "pid=-1 subj=? res=success"); > > > - } else { > > > - snprintf(usr2, sizeof(usr2), > > > - "op=resume-logging " > > > - "auid=%u pid=%d subj=%s res=success", > > > - cur_event->reply.signal_info->uid, > > > - cur_event->reply.signal_info->pid, > > > - cur_event->reply.signal_info->ctx); > > > - } > > > + audit_format_signal_info(usr2, sizeof(usr2), > > > + "resume-logging", > > > + &cur_event->reply, > > > + "success"); > > > > > > resume_logging(); > > > libdisp_resume(); > > > send_audit_event(AUDIT_DAEMON_RESUME, usr2); > > > > > > @@ -993,12 +981,8 @@ int main(int argc, char *argv[]) > > > > > > rc = get_reply(fd, &trep, rc); > > > if (rc > 0) { > > > > > > char txt[MAX_AUDIT_MESSAGE_LENGTH]; > > > > > > - snprintf(txt, sizeof(txt), > > > - "op=terminate auid=%u " > > > - "pid=%d subj=%s res=success", > > > - trep.signal_info->uid, > > > - trep.signal_info->pid, > > > - trep.signal_info->ctx); > > > + audit_format_signal_info(txt, sizeof(txt), "terminate", > > > + &trep, "success"); > > > > > > send_audit_event(AUDIT_DAEMON_END, txt); > > > > > > } > > > > > > } > > > > -- > > Linux-audit mailing list > > Linux-audit(a)redhat.com > > https://www.redhat.com/mailman/listinfo/linux-audit > > - RGB > > -- > Richard Guy Briggs <rgb(a)redhat.com&gt; > Sr. S/W Engineer, Kernel Security, Base Operating Systems > Remote, Ottawa, Red Hat Canada > IRC: rgb, SunRaycer > Voice: +1.647.777.2635, Internal: (81) 32635