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

[Peng Tao]

On Wed, Nov 20, 2013 at 2:37 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Nov 19, 2013 at 09:23:43PM +0800, Peng Tao wrote:
>> From: Amir Shehata <amir.shehata@xxxxxxxxx>
>>
>> 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.
>
Hi Greg,

Can you please be explicit about what build warning you saw?

I tried to reproduce it with gcc version 4.1.2 and 4.6.3 on my
machine, but didn't see any build warnings with this patch applied.

Thanks,
Tao
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