Re: [RFC PATCH v1 02/11] security: Add LSM_AUDIT_DATA_NS for namespace audit records

Mickaël Salaün
2026-04-01T18:59:40Z

On Wed, Mar 25, 2026 at 01:32:42PM +0100, Christian Brauner wrote:
> On Thu, Mar 12, 2026 at 11:04:35AM +0100, Mickaël Salaün wrote:
> > Add a new LSM audit data type LSM_AUDIT_DATA_NS that logs namespace
> > information in audit records. Two fields are provided, matching the
> > field names of struct ns_common:
> >
> > - ns_type: the CLONE_NEW* flag identifying the namespace type, logged in
> > hexadecimal.
> >
> > - inum: the proc inode number identifying a specific namespace instance.
> > Namespace inode numbers are allocated by proc_alloc_inum() via
> > ida_alloc_max() bounded to UINT_MAX, so the value always fits in 32
> > bits.
> >
> > A new audit data type is needed because no existing LSM_AUDIT_DATA_*
> > type carries namespace information. The closest alternatives (e.g.
> > LSM_AUDIT_DATA_TASK or LSM_AUDIT_DATA_NONE with custom strings) would
> > either lose the namespace type or require ad-hoc formatting that
> > bypasses the structured audit data union.
> >
> > Cc: Christian Brauner <brauner@kernel.org>
> > Cc: Günther Noack <gnoack@google.com>
> > Cc: Paul Moore <paul@paul-moore.com>
> > Signed-off-by: Mickaël Salaün <mic@digikod.net>
> > ---
> > include/linux/lsm_audit.h | 5 +++++
> > security/lsm_audit.c | 4 ++++
> > 2 files changed, 9 insertions(+)
> >
> > diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
> > index 382c56a97bba..6e20a56b8c22 100644
> > --- a/include/linux/lsm_audit.h
> > +++ b/include/linux/lsm_audit.h
> > @@ -78,6 +78,7 @@ struct common_audit_data {
> > #define LSM_AUDIT_DATA_NOTIFICATION 16
> > #define LSM_AUDIT_DATA_ANONINODE 17
> > #define LSM_AUDIT_DATA_NLMSGTYPE 18
> > +#define LSM_AUDIT_DATA_NS 19
> > union {
> > struct path path;
> > struct dentry *dentry;
> > @@ -100,6 +101,10 @@ struct common_audit_data {
> > int reason;
> > const char *anonclass;
> > u16 nlmsg_type;
> > + struct {
> > + u32 ns_type;
> > + unsigned int inum;
>
> fwiw, you might want to start the 64-bit namespace id as well.
> But either way:

Right now these numbers are generated by ida_alloc_max(), which return
an int. Is there an ongoing patch series for this change?

>
> Reviewed-by: Christian Brauner <brauner@kernel.org>
>