Re: [PATCH ghak21 V2 2/4] audit: link denied should not directly generate PATH record

[Richard Guy Briggs]

On 2018-03-12 11:05, Paul Moore wrote:
> On Mon, Mar 12, 2018 at 2:31 AM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> > Audit link denied events generate duplicate PATH records which disagree
> > in different ways from symlink and hardlink denials.
> > audit_log_link_denied() should not directly generate PATH records.
> > While we're at it, remove the now useless struct path argument.
> >
> > See: https://github.com/linux-audit/audit-kernel/issues/21
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > ---
> >  fs/namei.c            |  2 +-
> >  include/linux/audit.h |  6 ++----
> >  kernel/audit.c        | 17 ++---------------
> >  3 files changed, 5 insertions(+), 20 deletions(-)
> 
> I have no objection to the v2 change of removing the link parameter,
> but this patch can not be merged as-is because the v1 patch has
> already been merged into audit/next (as stated on the mailing list).

Yes, I self-NACKed that patch.

	https://www.redhat.com/archives/linux-audit/2018-March/msg00070.html

Is it not possible to drop it, or would you have to do a revert to avoid
a rebase?

> You need to respin this patch against audit/next and redo the
> subject/description to indicate that you are just removing the unused
> link parameter in this updated patch.

So the way I had it in my devel tree rather than squashing it...

> > diff --git a/fs/namei.c b/fs/namei.c
> > index 9cc91fb..50d2533 100644
> > --- a/fs/namei.c
> > +++ b/fs/namei.c
> > @@ -1011,7 +1011,7 @@ static int may_linkat(struct path *link)
> >         if (safe_hardlink_source(inode) || inode_owner_or_capable(inode))
> >                 return 0;
> >
> > -       audit_log_link_denied("linkat", link);
> > +       audit_log_link_denied("linkat");
> >         return -EPERM;
> >  }
> >
> > diff --git a/include/linux/audit.h b/include/linux/audit.h
> > index af410d9..75d5b03 100644
> > --- a/include/linux/audit.h
> > +++ b/include/linux/audit.h
> > @@ -146,8 +146,7 @@ extern void             audit_log_d_path(struct audit_buffer *ab,
> >                                              const struct path *path);
> >  extern void                audit_log_key(struct audit_buffer *ab,
> >                                           char *key);
> > -extern void                audit_log_link_denied(const char *operation,
> > -                                                 const struct path *link);
> > +extern void                audit_log_link_denied(const char *operation);
> >  extern void                audit_log_lost(const char *message);
> >
> >  extern int audit_log_task_context(struct audit_buffer *ab);
> > @@ -194,8 +193,7 @@ static inline void audit_log_d_path(struct audit_buffer *ab,
> >  { }
> >  static inline void audit_log_key(struct audit_buffer *ab, char *key)
> >  { }
> > -static inline void audit_log_link_denied(const char *string,
> > -                                        const struct path *link)
> > +static inline void audit_log_link_denied(const char *string)
> >  { }
> >  static inline int audit_log_task_context(struct audit_buffer *ab)
> >  {
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index 7026d69..e54deaf 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -2301,36 +2301,23 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
> >  /**
> >   * audit_log_link_denied - report a link restriction denial
> >   * @operation: specific link operation
> > - * @link: the path that triggered the restriction
> >   */
> > -void audit_log_link_denied(const char *operation, const struct path *link)
> > +void audit_log_link_denied(const char *operation)
> >  {
> >         struct audit_buffer *ab;
> > -       struct audit_names *name;
> >
> >         if (!audit_enabled || audit_dummy_context())
> >                 return;
> >
> > -       name = kzalloc(sizeof(*name), GFP_NOFS);
> > -       if (!name)
> > -               return;
> > -
> >         /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
> >         ab = audit_log_start(current->audit_context, GFP_KERNEL,
> >                              AUDIT_ANOM_LINK);
> >         if (!ab)
> > -               goto out;
> > +               return;
> >         audit_log_format(ab, "op=%s", operation);
> >         audit_log_task_info(ab, current);
> >         audit_log_format(ab, " res=0");
> >         audit_log_end(ab);
> > -
> > -       /* Generate AUDIT_PATH record with object. */
> > -       name->type = AUDIT_TYPE_NORMAL;
> > -       audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry));
> > -       audit_log_name(current->audit_context, name, link, 0, NULL);
> > -out:
> > -       kfree(name);
> >  }
> >
> >  /**
> > --
> > 1.8.3.1
> >
> 
> 
> 
> -- 
> paul moore
> www.paul-moore.com
> 
> --
> Linux-audit mailing list
> Linux-audit@xxxxxxxxxx
> https://www.redhat.com/mailman/listinfo/linux-audit

- 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