On Mon, Apr 4, 2022 at 4:18 PM Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
> On Tue, Mar 8, 2022 at 12:09 PM Christian Göttsche
> <cgzones@xxxxxxxxxxxxxx> wrote:
> >
> > Log the anonymous inode class name in the security hook
> > inode_init_security_anon. This name is the key for name based type
> > transitions on the anon_inode security class on creation. Example:
> >
> > type=AVC msg=audit(02/16/22 22:02:50.585:216) : avc: granted \
> > { create } for pid=2136 comm=mariadbd anonclass="[io_uring]" \
> > scontext=system_u:system_r:mysqld_t:s0 \
> > tcontext=system_u:system_r:mysqld_iouring_t:s0 tclass=anon_inode
> >
> > Add a new LSM audit data type holding the inode and the class name.
> >
> > Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> >
> > ---
> > v2:
> > - drop dev= and name= output for anonymous inodes, and hence simplify
> > the common_audit_data union member.
> > - drop WARN_ON() on empty name passed to inode_init_security_anon hook
> > ---
> > include/linux/lsm_audit.h | 2 ++
> > security/lsm_audit.c | 4 ++++
> > security/selinux/hooks.c | 4 ++--
> > 3 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
> > index 17d02eda9538..97a8b21eb033 100644
> > --- a/include/linux/lsm_audit.h
> > +++ b/include/linux/lsm_audit.h
> > @@ -76,6 +76,7 @@ struct common_audit_data {
> > #define LSM_AUDIT_DATA_IBENDPORT 14
> > #define LSM_AUDIT_DATA_LOCKDOWN 15
> > #define LSM_AUDIT_DATA_NOTIFICATION 16
> > +#define LSM_AUDIT_DATA_ANONINODE 17
> > union {
> > struct path path;
> > struct dentry *dentry;
> > @@ -96,6 +97,7 @@ struct common_audit_data {
> > struct lsm_ibpkey_audit *ibpkey;
> > struct lsm_ibendport_audit *ibendport;
> > int reason;
> > + const char *anonclass;
> > } u;
> > /* this union contains LSM specific data */
> > union {
> > diff --git a/security/lsm_audit.c b/security/lsm_audit.c
> > index 1897cbf6fc69..981f6a4e4590 100644
> > --- a/security/lsm_audit.c
> > +++ b/security/lsm_audit.c
> > @@ -433,6 +433,10 @@ static void dump_common_audit_data(struct audit_buffer *ab,
> > audit_log_format(ab, " lockdown_reason=\"%s\"",
> > lockdown_reasons[a->u.reason]);
> > break;
> > + case LSM_AUDIT_DATA_ANONINODE:
> > + audit_log_format(ab, " anonclass=");
> > + audit_log_untrustedstring(ab, a->u.anonclass);
>
> My apologies, I didn't notice this in the previous patch ... I don't
> think we need to log this as an untrusted string as the string value
> is coming from the kernel, not userspace, so we could rewrite the
> above as the following:
>
> audit_log_format(ab, " anonclass=%s", a->u.anonclass);
>
> ... if you are okay with that, I can make the change when I merge the
> patch or you can submit another revision, let me know which you would
> prefer.
>
> The rest of the patch looks good, thanks!
Hi Christian,
I just wanted to follow up on this as we are at -rc4 this week and if
we want this to go during the next merge window this would need to be
merged soon ...
--
paul-moore.com
