As far as I know Victor did not attempt to upstream his UBACKTRACE feature for audit.
Following Paul's point, maybe this is only useful in our internal use. Tracing fork/exec
in userland(auditctl) has been the way we are doing it. but we cannot afford to run it in
regression tests and valueable information was thus not captured and it's difficult for
folks to reproduce the issue.
On Tue, Feb 2, 2021 at 4:29 PM Daniel Walker <
danielwa@cisco.com
> wrote:
From: Phil Zhang <
xuanyzha@cisco.com
>
To ease the root cause analysis of SELinux AVCs, this new feature
traverses task structs to iteratively find all parent processes
starting with the denied process and ending at the kernel. Meanwhile,
it prints out the command lines and subject contexts of those parents.
This provides developers a clear view of how processes were spawned
and where transitions happened, without the need to reproduce the
issue and manually audit interesting events.
Example on bash over ssh:
$ runcon -u system_u -r system_r -t polaris_hm_t ls
...
type=PARENT msg=audit(1610548241.033:255): subj=root:unconfined_r:unconfined_t:s0-s0:c0.c1023 cmdline="-bash"
type=PARENT msg=audit(1610548241.033:255): subj=system_u:system_r:sshd_t:s0-s0:c0.c1023 cmdline="sshd: root@pts/0"
type=PARENT msg=audit(1610548241.033:255): subj=system_u:system_r:sshd_t:s0-s0:c0.c1023 cmdline="/tmp/sw/rp/0/0/rp_security/mount/usr/sbin/sshd
type=PARENT msg=audit(1610548241.033:255): subj=system_u:system_r:init_t:s0 cmdline="/init"
type=PARENT msg=audit(1610548241.033:255): subj=system_u:system_r:kernel_t:s0
...
Cc:
xe-linux-external@cisco.com
Signed-off-by: Phil Zhang <
xuanyzha@cisco.com
>
Signed-off-by: Daniel Walker <
danielwa@cisco.com
>
---
include/uapi/linux/audit.h | 5 ++-
init/Kconfig | 7 +++++
kernel/audit.c | 3 +-
kernel/auditsc.c | 64 ++++++++++++++++++++++++++++++++++++++
4 files changed, 77 insertions(+), 2 deletions(-)
This is just for development/testing of SELinux policy, right? It
seems like this is better done in userspace to me through a
combination of policy analysis and just understanding of how your
system is put together.
If you really need this information in the audit log for some
production use, it seems like you could audit the various
fork()/exec() syscalls to get an understanding of the various process
(sub)trees on the system. It would require a bit of work to sift
through the audit log and reconstruct the events that led to a process
being started, and generating the AVC you are interested in debugging,
but folks who live The Audit Life supposedly do this sort of thing a
lot (this sort of thing being tracing a process/session).