syslog-ng 3.6 may kill init process

[ghost]

If a destination program exits right before syslog-ng wants to terminate it, syslog-ng terminates init process instead of the program. If init process is immutable to TERM signal, on Ubuntu for example, it is not a problem. But otherwise you are in trouble, system goes down.

Tested on FreeBSD 8.4-p19 and FreeBSD 8.4-p34.
Syslog-ng 3.6.2 and 3.6.4 installed from freebsd package repository.
Hardware: HP Proliant DL380G5

CPU: Intel(R) Xeon(R) CPU E5440 @ 2.83GHz (2833.35-MHz K8-class CPU)
Origin = "GenuineIntel" Id = 0x10676 Family = 6 Model = 17 Stepping = 6
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
Features2=0xce3bd<SSE3,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,DCA,SSE4.1>
AMD Features=0x20100800<SYSCALL,NX,LM>
AMD Features2=0x1
TSC: P-state invariant
real memory = 4294967296 (4096 MB)
avail memory = 4097650688 (3907 MB)
ACPI APIC Table:
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
FreeBSD/SMP: 1 package(s) x 4 core(s)
cpu0 (BSP): APIC ID: 0
cpu1 (AP): APIC ID: 1
cpu2 (AP): APIC ID: 2
cpu3 (AP): APIC ID: 3

root@freebsd:~# uname -a
FreeBSD freebsd.local 8.4-RELEASE-p19 FreeBSD 8.4-RELEASE-p19 #0: Mon Nov 3 17:12:38 UTC 2014 root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC amd64

Configuration 1:
=== BEGIN =====
@Version: 3.6
@include "scl.conf"

source s_local { system(); internal(); };
destination d_local { program("not-existent-path"); }; # Trigger on stop, restart or reload
destination d_local1 { program("/usr/bin/true"); }; # Trigger on stop, restart or reload
log { source(s_local); destination(d_local); };
=== END ===

root@freebsd:# /usr/local/etc/rc.d/syslog-ng start
Starting syslog_ng.
root@freebsd:# /usr/local/etc/rc.d/syslog-ng reload # or restart, or stop
root@freebsd:~# Writing entropy file:.
Terminated
.
Enter full pathname of shell or RETURN for /bin/sh:

It may need a few syslog-ng reloads to trigger the issue.
Same effect is on restart and stop.

Configuration 2:
=== BEGIN =====
@Version: 3.6
@include "scl.conf"

source s_local { system(); internal(); };
destination d_local { program("/bin/cat"); }; # Trigger on "killall -1 cat syslog-ng"
log { source(s_local); destination(d_local); };
=== END ===

root@freebsd:# /usr/local/etc/rc.d/syslog-ng start
Starting syslog_ng.
root@freebsd:# killall -1 cat syslog-ng
root@freebsd:~# Writing entropy file:.
Terminated
.
Enter full pathname of shell or RETURN for /bin/sh:

It seems no problem with source programs.
It seems no problem with syslog-ng 3.5.
Other syslog-ng releases was not tested.

[bazsi]

seems to be caused by this patch:

37fd7fd

probably the getpgid() call fails, returns -1 which in turn means to kill the process group of the entire init process.

It must have been difficult to diagnose, thanks for the effort and the report.

[lbudai]

hmm.. I think you are right.
I'll setup a fix for this problem.

[lbudai]

@mcmurphy75 : #590 should solve the problem

[ihrwein]

@mcmurphy75 The fix for this issue has been merged (#590). Could you close this issue?

[ghost]

Unfortunately I have no development system to test the fix in my environment, but unchecked getpgid really looks like a cause of the problem. Good work. Thanks.