Some table unregister actions seem to be initiated by the kernel to
garbage collect unused tables that are not initiated by any userspace
actions. It was found to be necessary to add the subject credentials to
cover this case to reveal the source of these actions. A sample record:
The uid, auid, tty, ses and exe fields have not been included since they
are in the SYSCALL record and contain nothing useful in the non-user
context.
type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat family=bridge entries=0 op=unregister pid=153 subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
Signed-off-by: Richard Guy Briggs <[email protected]>
---
Changelog:
v6
- remove uid, auid fields as duplicates or unset
v5
- rebase on upstreamed ghak28 on audit/next v5.7-rc1
- remove tty, ses and exe fields as duplicates or unset
- drop upstreamed patches 1&2 from set
v4
- rebase on audit/next v5.7-rc1
- fix checkpatch.pl errors/warnings in 1/3 and 2/3
v3
- rebase on v5.6-rc1 audit/next
- change audit_nf_cfg to audit_log_nfcfg
- squash 2,3,4,5 to 1 and update patch descriptions
- add subject credentials to cover garbage collecting kernel threads
v2
- Rebase (audit/next 5.5-rc1) to get audit_context access and ebt_register_table ret code
- Split x_tables and ebtables updates
- Check audit_dummy_context
- Store struct audit_nfcfg params in audit_context, abstract to audit_nf_cfg() call
- Restore back to "table, family, entries" from "family, table, entries"
- Log unregistration of tables
- Add "op=" at the end of the AUDIT_NETFILTER_CFG record
- Defer nsid patch (ghak79) to once nsid patchset upstreamed (ghak32)
- Add ghak refs
- Ditch NETFILTER_CFGSOLO record
kernel/auditsc.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index cfe3486e5f31..e646055adb0b 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2557,12 +2557,21 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
enum audit_nfcfgop op)
{
struct audit_buffer *ab;
+ const struct cred *cred;
+ struct tty_struct *tty;
+ char comm[sizeof(current->comm)];
ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_NETFILTER_CFG);
if (!ab)
return;
audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
name, af, nentries, audit_nfcfgs[op].s);
+
+ cred = current_cred();
+ audit_log_format(ab, " pid=%u", task_pid_nr(current));
+ audit_log_task_context(ab); /* subj= */
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, get_task_comm(comm, current));
audit_log_end(ab);
}
EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
--
1.8.3.1
On 2020-05-20 12:51, Richard Guy Briggs wrote:
> Some table unregister actions seem to be initiated by the kernel to
> garbage collect unused tables that are not initiated by any userspace
> actions. It was found to be necessary to add the subject credentials to
> cover this case to reveal the source of these actions. A sample record:
>
> The uid, auid, tty, ses and exe fields have not been included since they
> are in the SYSCALL record and contain nothing useful in the non-user
> context.
>
> type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat family=bridge entries=0 op=unregister pid=153 subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
>
> Signed-off-by: Richard Guy Briggs <[email protected]>
Self-NACK. I forgot to remove cred and tty declarations.
> ---
> Changelog:
> v6
> - remove uid, auid fields as duplicates or unset
>
> v5
> - rebase on upstreamed ghak28 on audit/next v5.7-rc1
> - remove tty, ses and exe fields as duplicates or unset
> - drop upstreamed patches 1&2 from set
>
> v4
> - rebase on audit/next v5.7-rc1
> - fix checkpatch.pl errors/warnings in 1/3 and 2/3
>
> v3
> - rebase on v5.6-rc1 audit/next
> - change audit_nf_cfg to audit_log_nfcfg
> - squash 2,3,4,5 to 1 and update patch descriptions
> - add subject credentials to cover garbage collecting kernel threads
>
> v2
> - Rebase (audit/next 5.5-rc1) to get audit_context access and ebt_register_table ret code
> - Split x_tables and ebtables updates
> - Check audit_dummy_context
> - Store struct audit_nfcfg params in audit_context, abstract to audit_nf_cfg() call
> - Restore back to "table, family, entries" from "family, table, entries"
> - Log unregistration of tables
> - Add "op=" at the end of the AUDIT_NETFILTER_CFG record
> - Defer nsid patch (ghak79) to once nsid patchset upstreamed (ghak32)
> - Add ghak refs
> - Ditch NETFILTER_CFGSOLO record
>
> kernel/auditsc.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index cfe3486e5f31..e646055adb0b 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2557,12 +2557,21 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
> enum audit_nfcfgop op)
> {
> struct audit_buffer *ab;
> + const struct cred *cred;
> + struct tty_struct *tty;
> + char comm[sizeof(current->comm)];
>
> ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_NETFILTER_CFG);
> if (!ab)
> return;
> audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
> name, af, nentries, audit_nfcfgs[op].s);
> +
> + cred = current_cred();
> + audit_log_format(ab, " pid=%u", task_pid_nr(current));
> + audit_log_task_context(ab); /* subj= */
> + audit_log_format(ab, " comm=");
> + audit_log_untrustedstring(ab, get_task_comm(comm, current));
> audit_log_end(ab);
> }
> EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
> --
> 1.8.3.1
>
> --
> Linux-audit mailing list
> [email protected]
> https://www.redhat.com/mailman/listinfo/linux-audit
- RGB
--
Richard Guy Briggs <[email protected]>
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
On Wed, May 20, 2020 at 12:55 PM Richard Guy Briggs <[email protected]> wrote:
> On 2020-05-20 12:51, Richard Guy Briggs wrote:
> > Some table unregister actions seem to be initiated by the kernel to
> > garbage collect unused tables that are not initiated by any userspace
> > actions. It was found to be necessary to add the subject credentials to
> > cover this case to reveal the source of these actions. A sample record:
> >
> > The uid, auid, tty, ses and exe fields have not been included since they
> > are in the SYSCALL record and contain nothing useful in the non-user
> > context.
> >
> > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat family=bridge entries=0 op=unregister pid=153 subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
FWIW, that record looks good.
> > Signed-off-by: Richard Guy Briggs <[email protected]>
>
> Self-NACK. I forgot to remove cred and tty declarations.
--
paul moore
http://www.paul-moore.com
On Wednesday, May 20, 2020 2:40:45 PM EDT Paul Moore wrote:
> On Wed, May 20, 2020 at 12:55 PM Richard Guy Briggs <[email protected]> wrote:
> > On 2020-05-20 12:51, Richard Guy Briggs wrote:
> > > Some table unregister actions seem to be initiated by the kernel to
> > > garbage collect unused tables that are not initiated by any userspace
> > > actions. It was found to be necessary to add the subject credentials
> > > to cover this case to reveal the source of these actions. A sample
> > > record:
> > >
> > > The uid, auid, tty, ses and exe fields have not been included since
> > > they
> > > are in the SYSCALL record and contain nothing useful in the non-user
> > > context.
> > >
> > > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
> > > family=bridge entries=0 op=unregister pid=153
> > > subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
>
> FWIW, that record looks good.
It's severely broken
cat log.file
type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
family=bridge entries=0 op=unregister pid=153
subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
ausearch -if log.file --format text
At 19:33:40 12/31/1969 did-unknown
ausearch -if log.file --format csv
NODE,EVENT,DATE,TIME,SERIAL_NUM,EVENT_KIND,SESSION,SUBJ_PRIME,SUBJ_SEC,SUBJ_KIND,ACTION,RESULT,OBJ_PRIME,OBJ_SEC,OBJ_KIND,HOW
error normalizing NETFILTER_CFG
,NETFILTER_CFG,12/31/1969,19:33:40,0,,,,,,,,,,
This is unusable. This is why the bug was filed in the first place.
-Steve
> > > Signed-off-by: Richard Guy Briggs <[email protected]>
> >
> > Self-NACK. I forgot to remove cred and tty declarations.
On 2020-05-20 14:51, Steve Grubb wrote:
> On Wednesday, May 20, 2020 2:40:45 PM EDT Paul Moore wrote:
> > On Wed, May 20, 2020 at 12:55 PM Richard Guy Briggs <[email protected]> wrote:
> > > On 2020-05-20 12:51, Richard Guy Briggs wrote:
> > > > Some table unregister actions seem to be initiated by the kernel to
> > > > garbage collect unused tables that are not initiated by any userspace
> > > > actions. It was found to be necessary to add the subject credentials
> > > > to cover this case to reveal the source of these actions. A sample
> > > > record:
> > > >
> > > > The uid, auid, tty, ses and exe fields have not been included since
> > > > they
> > > > are in the SYSCALL record and contain nothing useful in the non-user
> > > > context.
> > > >
> > > > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
> > > > family=bridge entries=0 op=unregister pid=153
> > > > subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
> >
> > FWIW, that record looks good.
>
> It's severely broken
>
> cat log.file
> type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
> family=bridge entries=0 op=unregister pid=153
> subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
>
> ausearch -if log.file --format text
> At 19:33:40 12/31/1969 did-unknown
>
> ausearch -if log.file --format csv
> NODE,EVENT,DATE,TIME,SERIAL_NUM,EVENT_KIND,SESSION,SUBJ_PRIME,SUBJ_SEC,SUBJ_KIND,ACTION,RESULT,OBJ_PRIME,OBJ_SEC,OBJ_KIND,HOW
> error normalizing NETFILTER_CFG
> ,NETFILTER_CFG,12/31/1969,19:33:40,0,,,,,,,,,,
>
> This is unusable. This is why the bug was filed in the first place.
Have you applied this patchset?
https://www.redhat.com/archives/linux-audit/2020-May/msg00072.html
AUDIT_EVENT_LISTENER is also broken without this first patch.
> -Steve
>
> > > > Signed-off-by: Richard Guy Briggs <[email protected]>
> > >
> > > Self-NACK. I forgot to remove cred and tty declarations.
- RGB
--
Richard Guy Briggs <[email protected]>
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
On 2020-05-20 14:59, Richard Guy Briggs wrote:
> On 2020-05-20 14:51, Steve Grubb wrote:
> > On Wednesday, May 20, 2020 2:40:45 PM EDT Paul Moore wrote:
> > > On Wed, May 20, 2020 at 12:55 PM Richard Guy Briggs <[email protected]> wrote:
> > > > On 2020-05-20 12:51, Richard Guy Briggs wrote:
> > > > > Some table unregister actions seem to be initiated by the kernel to
> > > > > garbage collect unused tables that are not initiated by any userspace
> > > > > actions. It was found to be necessary to add the subject credentials
> > > > > to cover this case to reveal the source of these actions. A sample
> > > > > record:
> > > > >
> > > > > The uid, auid, tty, ses and exe fields have not been included since
> > > > > they
> > > > > are in the SYSCALL record and contain nothing useful in the non-user
> > > > > context.
> > > > >
> > > > > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
> > > > > family=bridge entries=0 op=unregister pid=153
> > > > > subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
> > >
> > > FWIW, that record looks good.
> >
> > It's severely broken
> >
> > cat log.file
> > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
> > family=bridge entries=0 op=unregister pid=153
> > subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2
> >
> > ausearch -if log.file --format text
> > At 19:33:40 12/31/1969 did-unknown
> >
> > ausearch -if log.file --format csv
> > NODE,EVENT,DATE,TIME,SERIAL_NUM,EVENT_KIND,SESSION,SUBJ_PRIME,SUBJ_SEC,SUBJ_KIND,ACTION,RESULT,OBJ_PRIME,OBJ_SEC,OBJ_KIND,HOW
> > error normalizing NETFILTER_CFG
> > ,NETFILTER_CFG,12/31/1969,19:33:40,0,,,,,,,,,,
> >
> > This is unusable. This is why the bug was filed in the first place.
>
> Have you applied this patchset?
> https://www.redhat.com/archives/linux-audit/2020-May/msg00072.html
>
> AUDIT_EVENT_LISTENER is also broken without this first patch.
And EVENT_LISTENER also needs this patch:
https://github.com/linux-audit/audit-userspace/pull/114/commits/27daa6fca534b30199040d0ad05420a8331ab421
> > -Steve
> >
> > > > > Signed-off-by: Richard Guy Briggs <[email protected]>
> > > >
> > > > Self-NACK. I forgot to remove cred and tty declarations.
>
> - RGB
- RGB
--
Richard Guy Briggs <[email protected]>
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