Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/directory v6

[Tejun Heo]

Hello, Vasiliy.

On Tue, Sep 06, 2011 at 02:15:18PM +0400, Vasiliy Kulikov wrote:
>   c) If dentry is lazily dropped on each access attempt (or each illegal
>      access) then PID2 can:
> 
>      i) read dentry line of /proc/slabinfo
>      ii) call link(2) against /proc/PID/fd, which invalidates the
>          specific dentry
>      iii) re-read dentry line of /proc/slabinfo.  If it has decreased by
>          one, the dentry existed before (ii).

If we really worry about this, probably the right thing to do is
hiding slabinfo from mortal UIDs instead of worrying about what
exactly are freed or not from each user.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/