Re: [PATCH] bpf: emit audit messages upon successful prog load and unload
On Wed, Nov 20, 2019 at 4:49 PM Alexei Starovoitov
<alexei.starovoitov(a)gmail.com> wrote:
On Wed, Nov 20, 2019 at 1:46 PM Daniel Borkmann
<daniel(a)iogearbox.net> wrote:
> On 11/20/19 10:38 PM, Jiri Olsa wrote:
> > From: Daniel Borkmann <daniel(a)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 20 12:45:51 2019
> > type=PROCTITLE msg=audit(1574271951.590:8974):
proctitle="./test_verifier"
> > type=SYSCALL msg=audit(1574271951.590:8974): arch=c000003e syscall=321
success=yes exit=14 a0=5 a1=7ffe2d923e80 a2=78 a3=0 items=0 ppid=742 pid=949 auid=0 uid=0
gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=2
comm="test_verifier"
exe="/root/bpf-next/tools/testing/selftests/bpf/test_verifier"
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
> > type=UNKNOWN[1334] msg=audit(1574271951.590:8974): auid=0 uid=0 gid=0 ses=2
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 pid=949
comm="test_verifier"
exe="/root/bpf-next/tools/testing/selftests/bpf/test_verifier" prog-id=3260
event=LOAD
> > ----
> > time->Wed Nov 20 12:45:51 2019
> > type=UNKNOWN[1334] msg=audit(1574271951.590:8975): prog-id=3260 event=UNLOAD
> > ----
> > [...]
> >
> > Signed-off-by: Daniel Borkmann <daniel(a)iogearbox.net>
> > Signed-off-by: Jiri Olsa <jolsa(a)kernel.org>
>
> LGTM, thanks for the rebase!
Applied to bpf-next. Thanks!
[NOTE: added linux-audit to the To/CC line]
Wait a minute, why was the linux-audit list not CC'd on this? Why are
you merging a patch into -next that adds to the uapi definition *and*
creates a new audit record while we are at -rc8?
Aside from that I'm concerned that you are relying on audit userspace
changes that might not be okay; I see the PR below, but I don't see
any comment on it from Steve (it is his audit userspace). I also
don't see a corresponding test added to the audit-testsuite, which is
a common requirement for new audit functionality (link below). I'm
also fairly certain we don't want this new BPF record to look like how
you've coded it up in bpf_audit_prog(); duplicating the fields with
audit_log_task() is wrong, you've either already got them via an
associated record (which you get from passing non-NULL as the first
parameter to audit_log_start()), or you don't because there is no
associated syscall/task (which you get from passing NULL as the first
parameter). Please revert, un-merge, etc. this patch from bpf-next;
it should not go into Linus' tree as written.
Audit userspace PR:
* https://github.com/linux-audit/audit-userspace/pull/104
Audit test suite:
* https://github.com/linux-audit/audit-testsuite
Audit folks, here is a link to the thread in the archives:
* https://lore.kernel.org/bpf/20191120213816.8186-1-jolsa@kernel.org/T/#u
--
paul moore
www.paul-moore.com