Re: [PATCH ghak90 V5 04/10] audit: log container info of syscalls

From: Richard Guy Briggs
Date: Wed Mar 27 2019 - 18:10:29 EST

On 2019-03-27 22:01, Ondrej Mosnacek wrote:
> On Fri, Mar 15, 2019 at 7:34 PM Richard Guy Briggs <rgb@xxxxxxxxxx> 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
> >
> > See: https://github.com/linux-audit/audit-kernel/issues/90
> > See: https://github.com/linux-audit/audit-userspace/issues/51
> > See: https://github.com/linux-audit/audit-testsuite/issues/64
> > See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > Acked-by: Serge Hallyn <serge@xxxxxxxxxx>
> > Acked-by: Steve Grubb <sgrubb@xxxxxxxxxx>
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
>
> Barring one minor nit below,
>
> Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
>
> > ---
> > include/linux/audit.h | 5 +++++
> > include/uapi/linux/audit.h | 1 +
> > kernel/audit.c | 21 +++++++++++++++++++++
> > kernel/auditsc.c | 2 ++
> > 4 files changed, 29 insertions(+)
> >
> > diff --git a/include/linux/audit.h b/include/linux/audit.h
> > index 301337776193..43438192ca2a 100644
> > --- a/include/linux/audit.h
> > +++ b/include/linux/audit.h
> > @@ -199,6 +199,8 @@ static inline u64 audit_get_contid(struct task_struct *tsk)
> > return tsk->audit->contid;
> > }
> >
> > +extern void audit_log_contid(struct audit_context *context, u64 contid);
> > +
> > extern u32 audit_enabled;
> > #else /* CONFIG_AUDIT */
> > static inline int audit_alloc(struct task_struct *task)
> > @@ -265,6 +267,9 @@ static inline u64 audit_get_contid(struct task_struct *tsk)
> > return AUDIT_CID_UNSET;
> > }
> >
> > +static inline void audit_log_contid(struct audit_context *context, u64 contid)
> > +{ }
> > +
> > #define audit_enabled AUDIT_OFF
> > #endif /* CONFIG_AUDIT */
> >
> > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> > index d475cf3b4d7f..a6383e28b2c8 100644
> > --- a/include/uapi/linux/audit.h
> > +++ b/include/uapi/linux/audit.h
> > @@ -115,6 +115,7 @@
> > #define AUDIT_REPLACE 1329 /* Replace auditd if this packet unanswerd */
> > #define AUDIT_KERN_MODULE 1330 /* Kernel Module events */
> > #define AUDIT_FANOTIFY 1331 /* Fanotify access decision */
> > +#define AUDIT_CONTAINER_ID 1332 /* Container ID */
> >
> > #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
> > #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index b5c702abeb42..8cc0e88d7f2a 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -2127,6 +2127,27 @@ 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", contid);
>
> Just realized that you *might* get a compiler/static checker warning
> since u64 could technically be something else than unsigned long long
> on some arches... maybe this is not case in the kernel, but might be
> safer to cast it to unsigned long long before passing to
> audit_log_format(). Possibly there are similar occurrences in previous
> (later) patches that I didn't (won't) notice.

Ok, since it is guaranteed to be at least 64 bits, a cast won't truncate
it.

> > + audit_log_end(ab);
> > + return;
> > +}
> > +EXPORT_SYMBOL(audit_log_contid);
> > +
> > void audit_log_key(struct audit_buffer *ab, char *key)
> > {
> > audit_log_format(ab, " key=");
> > diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> > index 8090eff7868d..a8c8b44b954d 100644
> > --- a/kernel/auditsc.c
> > +++ b/kernel/auditsc.c
> > @@ -1548,6 +1548,8 @@ static void audit_log_exit(void)
> >
> > audit_log_proctitle();
> >
> > + audit_log_contid(context, audit_get_contid(current));
> > +
> > /* Send end of event record to help user space know we are finished */
> > ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
> > if (ab)
>
> Ondrej Mosnacek <omosnace at redhat dot com>

- 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