Re: [PATCH ghak90 V6 04/10] audit: log container info of syscalls

Paul Moore
2019-05-30T14:34:22Z

On Thu, May 30, 2019 at 10:09 AM Richard Guy Briggs <rgb@redhat.com> wrote:
>
> On 2019-05-30 15:08, Ondrej Mosnacek wrote:
> > On Thu, May 30, 2019 at 12:16 AM Paul Moore <paul@paul-moore.com> wrote:
> > > On Mon, Apr 8, 2019 at 11:40 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> > > >
> > > > Create a new audit record AUDIT_CONTAINER_ID to document the audit
> > > > container identifier of a process if it is present.
> > > >
> > > > Called from audit_log_exit(), syscalls are covered.
> > > >
> > > > A sample raw event:
> > > > type=SYSCALL msg=audit(1519924845.499:257): arch=c000003e syscall=257 success=yes exit=3 a0=ffffff9c a1=56374e1cef30 a2=241 a3=1b6 items=2 ppid=606 pid=635 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="bash" exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key="tmpcontainerid"
> > > > type=CWD msg=audit(1519924845.499:257): cwd="/root"
> > > > type=PATH msg=audit(1519924845.499:257): item=0 name="/tmp/" inode=13863 dev=00:27 mode=041777 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:tmp_t:s0 nametype= PARENT cap_fp=0 cap_fi=0 cap_fe=0 cap_fver=0
> > > > type=PATH msg=audit(1519924845.499:257): item=1 name="/tmp/tmpcontainerid" inode=17729 dev=00:27 mode=0100644 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=CREATE cap_fp=0 cap_fi=0 cap_fe=0 cap_fver=0
> > > > type=PROCTITLE msg=audit(1519924845.499:257): proctitle=62617368002D6300736C65657020313B206563686F2074657374203E202F746D702F746D70636F6E7461696E65726964
> > > > type=CONTAINER_ID msg=audit(1519924845.499:257): contid=123458
> > > >
> > > > Please see the github audit kernel issue for the main feature:
> > > > https://github.com/linux-audit/audit-kernel/issues/90
> > > > Please see the github audit userspace issue for supporting additions:
> > > > https://github.com/linux-audit/audit-userspace/issues/51
> > > > Please see the github audit testsuiite issue for the test case:
> > > > https://github.com/linux-audit/audit-testsuite/issues/64
> > > > Please see the github audit wiki for the feature overview:
> > > > https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
> > > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > > > Acked-by: Serge Hallyn <serge@hallyn.com>
> > > > Acked-by: Steve Grubb <sgrubb@redhat.com>
> > > > Acked-by: Neil Horman <nhorman@tuxdriver.com>
> > > > Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > > ---
> > > > include/linux/audit.h | 5 +++++
> > > > include/uapi/linux/audit.h | 1 +
> > > > kernel/audit.c | 20 ++++++++++++++++++++
> > > > kernel/auditsc.c | 20 ++++++++++++++------
> > > > 4 files changed, 40 insertions(+), 6 deletions(-)
> > >
> > > ...
> > >
> > > > diff --git a/kernel/audit.c b/kernel/audit.c
> > > > index 182b0f2c183d..3e0af53f3c4d 100644
> > > > --- a/kernel/audit.c
> > > > +++ b/kernel/audit.c
> > > > @@ -2127,6 +2127,26 @@ void audit_log_session_info(struct audit_buffer *ab)
> > > > audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
> > > > }
> > > >
> > > > +/*
> > > > + * audit_log_contid - report container info
> > > > + * @context: task or local context for record
> > > > + * @contid: container ID to report
> > > > + */
> > > > +void audit_log_contid(struct audit_context *context, u64 contid)
> > > > +{
> > > > + struct audit_buffer *ab;
> > > > +
> > > > + if (!audit_contid_valid(contid))
> > > > + return;
> > > > + /* Generate AUDIT_CONTAINER_ID record with container ID */
> > > > + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER_ID);
> > > > + if (!ab)
> > > > + return;
> > > > + audit_log_format(ab, "contid=%llu", (unsigned long long)contid);
> > >
> > > We have a consistency problem regarding how to output the u64 contid
> > > values; this function uses an explicit cast, others do not. According
> > > to Documentation/core-api/printk-formats.rst the recommendation for
> > > u64 is %llu (or %llx, if you want hex). Looking quickly through the
> > > printk code this appears to still be correct. I suggest we get rid of
> > > the cast (like it was in v5).
> >
> > IIRC it was me who suggested to add the casts. I didn't realize that
> > the kernel actually guarantees that "%llu" will always work with u64.
> > Taking that into account I rescind my request to add the cast. Sorry
> > for the false alarm.
>
> Yeah, just remove the cast.

Okay, this is trivial enough I'll take care of this during the merge
with a note.

--
paul moore