Re: [PATCH ghak21 V2 3/4] audit: add refused symlink to audit_names

From: Steve Grubb
Date: Tue Mar 13 2018 - 04:35:03 EST


On Mon, 12 Mar 2018 11:52:56 -0400
Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:

> On 2018-03-12 11:53, Paul Moore wrote:
> > On Mon, Mar 12, 2018 at 11:26 AM, Richard Guy Briggs
> > <rgb@xxxxxxxxxx> wrote:
> > > On 2018-03-12 11:12, Paul Moore wrote:
> > >> On Mon, Mar 12, 2018 at 2:31 AM, Richard Guy Briggs
> > >> <rgb@xxxxxxxxxx> wrote:
> > >> > Audit link denied events for symlinks had duplicate PATH
> > >> > records rather than just updating the existing PATH record.
> > >> > Update the symlink's PATH record with the current dentry and
> > >> > inode information.
> > >> >
> > >> > See: https://github.com/linux-audit/audit-kernel/issues/21
> > >> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > >> > ---
> > >> > fs/namei.c | 1 +
> > >> > 1 file changed, 1 insertion(+)
> > >>
> > >> Why didn't you include this in patch 4/4 like I asked during the
> > >> previous review?
> > >
> > > Please see the last comment of:
> > > https://www.redhat.com/archives/linux-audit/2018-March/msg00070.html
> >
> > Yes, I just saw that ... I hadn't seen your replies on the v1
> > patches until I had finished reviewing v2. I just replied to that
> > mail in the v1 thread, but basically you need to figure out what is
> > necessary here and let us know. If I have to figure it out it
> > likely isn't going to get done with enough soak time prior to the
> > upcoming merge window.
>
> Steve? I was hoping you could chime in here.

If the CWD record will always be the same as the PARENT record, then we
do not need the parent record. Duplicate information is bad. Like all
the duplicate SYSCALL information.

-Steve


> I'd just include it for completeness unless Steve thinks it will stand
> on its own and doesn't want the overhead.
>
> > >> > diff --git a/fs/namei.c b/fs/namei.c
> > >> > index 50d2533..00f5041 100644
> > >> > --- a/fs/namei.c
> > >> > +++ b/fs/namei.c
> > >> > @@ -945,6 +945,7 @@ static inline int may_follow_link(struct
> > >> > nameidata *nd) if (nd->flags & LOOKUP_RCU)
> > >> > return -ECHILD;
> > >> >
> > >> > + audit_inode(nd->name, nd->stack[0].link.dentry, 0);
> > >> > audit_log_link_denied("follow_link",
> > >> > &nd->stack[0].link); return -EACCES;
> > >> > }
> > >>
> > >> paul moore
> > >
> > > - RGB
> >
> > paul moore
>
> - 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
>
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