Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/directory v12

From: Cyrill Gorcunov
Date: Fri Sep 16 2011 - 14:07:43 EST


On Fri, Sep 16, 2011 at 09:56:18PM +0400, Vasiliy Kulikov wrote:
...
> >
> > v14: (by Vasiliy Kulikov)
> > - for security reason map_files/ entries are allowed for
> > readers with CAP_SYS_ADMIN credentials granted only
>
> This changelog is currently much longer than the commit description text ;)

Yes, I know ;) I would like to keep it (to appreciate everyone who spent time
in review and feedback).
...
>
> > +
> > + inode = dentry->d_inode;
> > + task = get_proc_task(inode);
> > + if (!task)
> > + goto out_notask;
> > +
> > + if (!ptrace_may_access(task, PTRACE_MODE_READ))
> > + goto out;
>
> While this is not needed with capable() check, it's OK to keep it for
> the future more finegranted access checks.

yeah

>
> BTW, not a big deal, but probably you should return -EACCES on
> !capable() as file presence is not an issue in this case.
>
> if (!ptrace_may_access(task, PTRACE_MODE_READ))
> goto out_notask;
>
> status = -EACCES;
> if (!capable(CAP_SYS_ADMIN))
> goto out_notask;
>
> status = 0;
>
>

That's not a proble to fix it actually. So can I fix it and
put some tage here (Reviewed or something?).

Cyrill
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