Re: [PATCH 4/9] staging/lustre/lnet: Fix assert on empty group in selftest module

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Nov 19, 2013 at 09:23:43PM +0800, Peng Tao wrote:
> From: Amir Shehata <amir.shehata@intel.com>
> 
> The core of the issue is that the selftest module doesn't sanitize its
> own API, but it depends on lst utility to do such checks.  As a result
> this issue manifests itself in this particular LU through an assert
> on an empty group.  If the NID is misspelled then an empty group is
> added.  An error output is provided, but if that's never checked in a
> batch script, as is the case with this issue, then the script will try
> to add an empty group to a test to run in a batch, and that will cause
> an assert
> 
> The fix is two fold.  Ensure that lst utility checks that a group is
> added with at least one node.  If not the group is subsequently
> deleted.  And the add_test command would fail, since the group no
> longer exists.
> 
> The second fix is to ensure that the kernel module itself sanitizes
> its own API in this particular case, so that if a different utility is
> used other than lst to communicate with the selftest kernel module
> then this error would be caught.  This fix looks up the batch and the
> groups, src and dst, in the ioctl handle and sanitizes that input at
> this point.  If the group looked up either doesn't exist or doesn't
> have at least one ACTIVE node, then the command fails.
> 
> NOTE:there are many other cases in the code where the selftest kernel
> module doesn't check for sanity of the input, but depends totally on
> the lst module to do such checks.  Particularly around length of
> strings passed in.  Thus it is possible to crash the selftest module
> if someone tries to create another userspace app to communicate with
> the selftest kernel module without ensuring sanity of the params sent
> to the kernel module.  In effect, it's always assumed that lst is the
> front end for selftest and no other front end is to be used.

This patch adds build warnings to the kernel build process, so I can't
apply it, sorry.  Please fix that up before sending it again.

greg k-h