Re: [PATCH v4 3/3] audit: add OPENAT2 record to list how

[Richard Guy Briggs]

On 2021-10-04 12:08, Paul Moore wrote:
> On Wed, May 19, 2021 at 4:02 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> >
> > Since the openat2(2) syscall uses a struct open_how pointer to communicate
> > its parameters they are not usefully recorded by the audit SYSCALL record's
> > four existing arguments.
> >
> > Add a new audit record type OPENAT2 that reports the parameters in its
> > third argument, struct open_how with fields oflag, mode and resolve.
> >
> > The new record in the context of an event would look like:
> > time->Wed Mar 17 16:28:53 2021
> > type=PROCTITLE msg=audit(1616012933.531:184): proctitle=73797363616C6C735F66696C652F6F70656E617432002F746D702F61756469742D7465737473756974652D737641440066696C652D6F70656E617432
> > type=PATH msg=audit(1616012933.531:184): item=1 name="file-openat2" inode=29 dev=00:1f mode=0100600 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 cap_frootid=0
> > type=PATH msg=audit(1616012933.531:184): item=0 name="/root/rgb/git/audit-testsuite/tests" inode=25 dev=00:1f mode=040700 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=PARENT cap_fp=0 cap_fi=0 cap_fe=0 cap_fver=0 cap_frootid=0
> > type=CWD msg=audit(1616012933.531:184): cwd="/root/rgb/git/audit-testsuite/tests"
> > type=OPENAT2 msg=audit(1616012933.531:184): oflag=0100302 mode=0600 resolve=0xa
> > type=SYSCALL msg=audit(1616012933.531:184): arch=c000003e syscall=437 success=yes exit=4 a0=3 a1=7ffe315f1c53 a2=7ffe315f1550 a3=18 items=2 ppid=528 pid=540 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 ses=1 comm="openat2" exe="/root/rgb/git/audit-testsuite/tests/syscalls_file/openat2" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key="testsuite-1616012933-bjAUcEPO"
> >
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > Link: https://lore.kernel.org/r/d23fbb89186754487850367224b060e26f9b7181.1621363275.git.rgb@xxxxxxxxxx
> > ---
> >  fs/open.c                  |  2 ++
> >  include/linux/audit.h      | 10 ++++++++++
> >  include/uapi/linux/audit.h |  1 +
> >  kernel/audit.h             |  2 ++
> >  kernel/auditsc.c           | 18 +++++++++++++++++-
> >  5 files changed, 32 insertions(+), 1 deletion(-)
> 
> ...
> 
> > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> > index cd2d8279a5e4..67aea2370c6d 100644
> > --- a/include/uapi/linux/audit.h
> > +++ b/include/uapi/linux/audit.h
> > @@ -118,6 +118,7 @@
> >  #define AUDIT_TIME_ADJNTPVAL   1333    /* NTP value adjustment */
> >  #define AUDIT_BPF              1334    /* BPF subsystem */
> >  #define AUDIT_EVENT_LISTENER   1335    /* Task joined multicast read socket */
> > +#define AUDIT_OPENAT2          1336    /* Record showing openat2 how args */
> 
> As a heads-up, I had to change the AUDIT_OPENAT2 value to 1337 as the
> 1336 value is already in use by AUDIT_URINGOP.  It wasn't caught
> during my initial build test as the LSM/audit io_uring patches are in
> selinux/next and not audit/next, it wasn't until the kernel-secnext
> build was merging everything for its test run that the collision
> occurred.  I'll be updating the audit/next tree with the new value
> shortly.

I was expecting a conflict, so thanks for the heads up, Paul.

Steve: This affects the audit userspace support for this patchset
previously published 2021-05-19 as:
	https://github.com/rgbriggs/audit-userspace/tree/ghau-openat2

The update is here:
	https://github.com/rgbriggs/audit-userspace/tree/ghau-openat2.v2

And a PR has been created:
	https://github.com/linux-audit/audit-userspace/pull/219

> paul moore

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635