On Tue, 2014-02-18 at 15:50 -0500, Richard Guy Briggs wrote:
> On 14/02/14, Eric Paris wrote:
> > On Fri, 2014-02-14 at 15:52 -0500, Richard Guy Briggs wrote:
> > > On 14/02/14, Richard Guy Briggs wrote:
> > > > On 14/02/14, Eric Paris wrote:
> > > > > On Fri, 2014-02-14 at 15:23 -0500, Richard Guy Briggs wrote:
> > > > > > The AUDIT_SECCOMP record looks something like this:
> > > > > >
> > > > > > type=SECCOMP msg=audit(1373478171.953:32775): auid=4325 uid=4325
> > > > > > gid=4325 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0
> > > > > > pid=12381 comm="test" sig=31 syscall=231 compat=0 ip=0x39ea8bca89
> > > > > > code=0x0
> > > > > >
> > > > > > In order to determine what syscall 231 maps to, we need to have the
> > > > > > arch= field right before it.
> > > > > >
> > > > > > To see the event, compile this test.c program:
> > > > > >
> > > > > > =====
> > > > > > int main(void)
> > > > > > {
> > > > > > return seccomp_load(seccomp_init(SCMP_ACT_KILL));
> > > > > > }
> > > > > > =====
> > > > > >
> > > > > > gcc -g test.c -o test -lseccomp
> > > > > >
> > > > > > After running the program, find the record by: ausearch --start
> > > > > > recent -m SECCOMP -i
> > > > > > ---
> > > > > > kernel/auditsc.c | 1 +
> > > > > > 1 files changed, 1 insertions(+), 0 deletions(-)
> > > > > >
> > > > > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > > > > index 6874c1f..c464d44 100644
> > > > > > --- a/kernel/auditsc.c
> > > > > > +++ b/kernel/auditsc.c
> > > > > > @@ -2412,6 +2412,7 @@ void __audit_seccomp(unsigned long syscall,
> > > > > > long signr, int code)
> > > > > > return;
> > > > > > audit_log_task(ab);
> > > > > > audit_log_format(ab, " sig=%ld", signr);
> > > > > > + audit_log_format(ab, " arch=%x", current->audit_context->arch);
> > > > >
> > > > >
> > > > > What happens if the task does not have current->audit_context
> > > > > allocated?
> > > > > Seems possible if signr is non-zero...
> > > >
> > > > I had assumed that since we got this far, that there was an audit
> > > > context. This was my first patch:
> > >
> > > Sorry, pulled the trigger too fast:
> > >
> > > ---
> > > kernel/auditsc.c | 6 ++++++
> > > 1 files changed, 6 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > > index 6874c1f..3023d03 100644
> > > --- a/kernel/auditsc.c
> > > +++ b/kernel/auditsc.c
> > > @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> > > void __audit_seccomp(unsigned long syscall, long signr, int code)
> > > {
> > > struct audit_buffer *ab;
> > > + struct audit_context *context audit_get_context(current, 0, 0);
> >
> > missing '=' but this isn't what audit_get_context() does... it's
> > crappy naming... I'd think a combo of audit_dummy_context() and
> > current->audit_context would be most appropriate.
>
> Ok. I think I finally understand audit_dummy_context(). Thanks for the
> hint. However, it appears it is not useful in this sitation, since if
> there is an audit_context, even a dummy context, it appears arch is
> filled in.
get a good commit message and feel free to add my Acked-by.
-Eric
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> @@ -2406,12 +2406,18 @@ void audit_core_dumps(long signr)
> void __audit_seccomp(unsigned long syscall, long signr, int code)
> {
> struct audit_buffer *ab;
> + struct audit_context *context = current->audit_context;
>
> ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP);
> if (unlikely(!ab))
> return;
> audit_log_task(ab);
> audit_log_format(ab, " sig=%ld", signr);
> + audit_log_format(ab, " arch=");
> + if (context)
> + audit_log_format(ab, "%x", context->arch);
> + else
> + audit_log_format(ab, "(null)");
> audit_log_format(ab, " syscall=%ld", syscall);
> audit_log_format(ab, " compat=%d", is_compat_task());
> audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current));
>
> - RGB
>
> --
> Richard Guy Briggs <rbri...@redhat.com>
> Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems,
> Red Hat
> Remote, Ottawa, Canada
> Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545
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