On 15/09/11, Kangkook Jee wrote: > Hi Richard, Hi Kangkook,
> I also did the same experiment for the latest distributions of Fedora > core and Debian and here’s the results. > > Fedora-22 (64-bit, 4.0.4-301.fc22.x86_64): Problem reproduced. > Debian-8 (64-bit, 3.16.0-4-amd64): Problem reproduced > > Btw, Burn Alting ([email protected]) suggested me to append audit=1 > to kernel flag. I added the option to boot-loader (grub) and problem > went away. On all systems? This is expected behaviour. Sorry I was not more explicit in asking you to test that. I guess it was implied by asking what the settings for the kernel command line were. Now the surprising bit is that CentOS does not demonstrate the problem without audit=1 in the command line, which leads me to wonder if they have set "u32 audit_enabled = 1;" around line 83 of kernel/audit.c in their kernel source. It would surprise me if they did, but it would not be completely unreasonable. > Regards, Kangkook > > > On Sep 11, 2015, at 12:24 PM, Richard Guy Briggs <[email protected]> wrote: > > On 15/09/11, Kangkook Jee wrote: > >> From the previous reply, I think I misunderstood your question regarding > >> kernel command line. > >> Here’s "cat /proc/cmdline” results for distributions that I’ve > >> experimented. > >> > >> Ubuntu 14.04 (64-bit): > >> BOOT_IMAGE=/boot/vmlinuz-3.13.0-58-generic > >> root=UUID=7505f862-ce46-49e5-9d1c-e4e307844889 ro text quiet splash > >> vt.handoff=7 > >> > >> Ubuntu 12.04 (64-bit): > >> BOOT_IMAGE=/boot/vmlinuz-3.13.0-32-generic > >> root=UUID=5be789be-9b0c-463e-bd18-42bfa79fb24c ro quiet splash > >> > >> CentOS 7 (64-bit): > >> BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.x86_64 root=/dev/mapper/centos-root > >> ro rd.lvm.lv=centos/root rd.lvm.lv=centos/swap crashkernel=auto rhgb quiet > >> LANG=en_US.UTF-8 > >> > >> CentOS 6 (64-bit): > >> ro root=UUID=a7d44560-adcc-4000-9584-8b9fcf2afd74 rd_NO_LUKS rd_NO_LVM > >> LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=129M@0M > >> KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet > >> > >> I don’t see any audit=<value> entries from all examples above. > > > > Yes, this is what I was seeking from you. And you are correct, none of > > them have audit=1 as I was hoping from at least CentOS. There is a > > chance that the CentOS kernel was compiled with audit=1 hardcoded, but I > > think that is a pretty small chance... > > > > I'll have to look at this closer... But any Debian and Fedora data > > points that you can provide would certainly be useful. > > > >> /Kangkook > >> > >>> On Sep 11, 2015, at 5:50 AM, Richard Guy Briggs <[email protected]> wrote: > >>> > >>> On 15/09/10, Kangkook Jee wrote: > >>>> Hi all, > >>>> > >>>> I debugged a bit further to identify distributions that are affected by > >>>> the issue. > >>>> I repeated the same experiment with sshd from 3 more distributions. > >>>> > >>>> CentOS Linux release 7.1.1503 (64-bit, 3.10.0-229.el7.x86_64): Problem > >>>> NOT reproduced > >>>> CentOS release 6.6 (64-bit, 2.6.32-504.el6.x86_64): Problem NOT > >>>> reproduced > >>>> Ubuntu 12.04.5 LTS (64-bit, 3.13.0-32-generic): Problem reproduced > >>> > >>> For each of these examples, what is the value of the kernel command line > >>> "audit=<value>" if it is even present? It is possible that the CentOS > >>> examples include "audit=1" while Ubuntu omits the line. "cat > >>> /proc/cmdline" should tell you the answer. > >>> > >>>> After all, Ubuntu family are affected by the issue and I could confirm > >>>> that results are inconsistent across two different distribution > >>>> families. > >>> > >>> I would be curious what your results are with a recent Debian and with a > >>> recent Fedora. > >>> > >>>> If you can let us know how can we workaround the issue, it will be a > >>>> great help. > >>>> > >>>> Regards, Kangkook > >>>> > >>>> > >>>>> On Sep 9, 2015, at 11:50 PM, Kangkook Jee <[email protected]> wrote: > >>>>> > >>>>> Dear all, > >>>>> > >>>>> We are developing custom user space audit agent to gather system wide > >>>>> system > >>>>> call trace. While experimenting with various programs, we found out that > >>>>> processes (daemons) that started early (along with the system > >>>>> bootstrapping) do > >>>>> not report any audit events at all. These processes typically fall into > >>>>> PID > >>>>> range of less than 2000. Here’s how I reproduced the symptom with sshd > >>>>> daemon. > >>>>> > >>>>> 1. Reboot the system > >>>>> > >>>>> 2. Add and enable audit events > >>>>> # /sbin/auditctl -a exit,always -F arch=b64 -S clone -S close -S creat > >>>>> -S dup > >>>>> -S dup2 -S dup3 -S execve -S exit -S exit_group -S fork -S open > >>>>> -S openat > >>>>> -S unlink -S unlinkat -S vfork -S 288 -S accept -S bind -S > >>>>> connect > >>>>> -S listen -S socket -S socketpair > >>>>> # /sbin/auditctl -e1 -b 102400 > >>>>> > >>>>> 3. Connect to the system via ssh > >>>>> Audit messages generated only from child processes and none are seen > >>>>> from > >>>>> the original daemon. > >>>>> > >>>>> 4. Restart sshd > >>>>> # restart ssh > >>>>> > >>>>> 5. Connect again to the system via ssh > >>>>> Now, we see audit messages from both parent and child processes. > >>>>> > >>>>> I did the experiment from Ubuntu 14.04.2 LTS distribution (64-bit, > >>>>> kernel > >>>>> version 3.13.0-58-generic). > >>>>> > >>>>> I first wonder whether this is intended behavior of audit framework or > >>>>> not. If it is intended, I also want to know how can we configure auditd > >>>>> differently to capture system calls from all processes. > >>>>> > >>>>> Thanks a lot for your help in advance! > >>>>> > >>>>> Regards, Kangkook > >>> > >>> - RGB > > > > - RGB - RGB -- Richard Guy Briggs <[email protected]> Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote, Ottawa, Canada Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545 -- Linux-audit mailing list [email protected] https://www.redhat.com/mailman/listinfo/linux-audit
