Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751796AbaBRUut (ORCPT ); Tue, 18 Feb 2014 15:50:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38368 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750911AbaBRUus (ORCPT ); Tue, 18 Feb 2014 15:50:48 -0500 Date: Tue, 18 Feb 2014 15:50:44 -0500 From: Richard Guy Briggs To: Eric Paris Cc: linux-audit@redhat.com, linux-kernel@vger.kernel.org, Steve Grubb Subject: Re: [PATCH] audit: add arch field to seccomp event log Message-ID: <20140218205044.GL16640@madcap2.tricolour.ca> References: <4bc8c03bda84e004c331546e228b334811b03254.1392409147.git.rgb@redhat.com> <1392410961.2760.17.camel@localhost> <20140214205057.GF18807@madcap2.tricolour.ca> <20140214205218.GG18807@madcap2.tricolour.ca> <1392412322.2760.21.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1392412322.2760.21.camel@localhost> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/