[RFC] bpf: Emit audit messages upon successful prog load and unload

[Jiri Olsa]

On Thu, Nov 28, 2019 at 10:16:32AM +0100, Jiri Olsa wrote:
> From: Daniel Borkmann <daniel at iogearbox.net>
> 
> Allow for audit messages to be emitted upon BPF program load and
> unload for having a timeline of events. The load itself is in
> syscall context, so additional info about the process initiating
> the BPF prog creation can be logged and later directly correlated
> to the unload event.
> 
> The only info really needed from BPF side is the globally unique
> prog ID where then audit user space tooling can query / dump all
> info needed about the specific BPF program right upon load event
> and enrich the record, thus these changes needed here can be kept
> small and non-intrusive to the core.
> 
> Raw example output:
> 
>   # auditctl -D
>   # auditctl -a always,exit -F arch=x86_64 -S bpf
>   # ausearch --start recent -m 1334
>   ...
>   ----
>   time->Wed Nov 27 16:04:13 2019
>   type=PROCTITLE msg=audit(1574867053.120:84664): proctitle="./bpf"
>   type=SYSCALL msg=audit(1574867053.120:84664): arch=c000003e syscall=321   \
>     success=yes exit=3 a0=5 a1=7ffea484fbe0 a2=70 a3=0 items=0 ppid=7477    \
>     pid=12698 auid=1001 uid=1001 gid=1001 euid=1001 suid=1001 fsuid=1001    \
>     egid=1001 sgid=1001 fsgid=1001 tty=pts2 ses=4 comm="bpf"                \
>     exe="/home/jolsa/auditd/audit-testsuite/tests/bpf/bpf"                  \
>     subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
>   type=UNKNOWN[1334] msg=audit(1574867053.120:84664): prog-id=76 op=LOAD
>   ----
>   time->Wed Nov 27 16:04:13 2019
>   type=UNKNOWN[1334] msg=audit(1574867053.120:84665): prog-id=76 op=UNLOAD
>   ...
> 
> Signed-off-by: Daniel Borkmann <daniel at iogearbox.net>
> Co-developed-by: Jiri Olsa <jolsa at kernel.org>
> Signed-off-by: Jiri Olsa <jolsa at kernel.org>

fyi I prepared userspace changes:
  https://github.com/olsajiri/audit-userspace/commit/3108a81fa8d937f07b4c78be8ae00fcd3d64f94d
  https://github.com/olsajiri/audit-testsuite/commit/16888ea7f14fa0269feef623d2a96f15f9ea71c9

I'll sumbit github PRs once the kernel change is pulled in

thanks,
jirka