Isolated Hosts Configuration - Kernel_Obj

[Kainaat Singh]

Hello,

As we have no kernel image involved in Isolated hosts, why is there a kernel_obj config defined in the default config file as follows: Github

Best Regards

[Dmitry Vyukov]

On Fri, Mar 26, 2021 at 12:19 PM Kainaat Singh <savvy....@gmail.com> wrote:
>
> Hello,
>
> As we have no kernel image involved in Isolated hosts, why is there a kernel_obj config defined in the default config file as follows: Github

Kernel is still involved at least in the coverage report generation.

[Kainaat Singh]

So, this source code needs to be on the host or the target?

[Dmitry Vyukov]

On Fri, Mar 26, 2021 at 3:13 PM Kainaat Singh <savvy....@gmail.com> wrote:
>
> So, this source code needs to be on the host or the target?

Kernel source and object files need to be on the host.

> On Friday, 26 March 2021 at 12:26:21 UTC+1 Dmitry Vyukov wrote:
>>
>> On Fri, Mar 26, 2021 at 12:19 PM Kainaat Singh <savvy....@gmail.com> wrote:
>> >
>> > Hello,
>> >
>> > As we have no kernel image involved in Isolated hosts, why is there a kernel_obj config defined in the default config file as follows: Github
>>
>> Kernel is still involved at least in the coverage report generation.
>

> --
> You received this message because you are subscribed to the Google Groups "syzkaller" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+...@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller/9e481f2d-df00-44f3-862f-bcc14ca1991bn%40googlegroups.com.

[Kainaat Singh]

I have the source and object files on the host machine. I get the following error when I run syzkaller:

bitmap is not found, coverage filter disabled

Coverage is enabled on the target machine which the syzkaller's machine check verifies. I can see from debug logs that coverage is getting collected, for e.g.:

openat$i915=0xffffffffffffffff errno=13 cover=2547

Do I have to enable coverage filter in the config file for isolated host fuzzing?  

CovFilter covFilterCfg `json:"cover_filter"`

[Dmitry Vyukov]

On Thu, Apr 1, 2021 at 11:28 AM Kainaat Singh <savvy....@gmail.com> wrote:
>
> I have the source and object files on the host machine. I get the following error when I run syzkaller:
>
> bitmap is not found, coverage filter disabled

This is not an error and it does not affect fuzzing in any way, this
is just a printf:
https://github.com/google/syzkaller/blob/master/executor/cov_filter.h#L23

> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller/8cb476bb-02d7-4fd7-a5dd-02f06729de92n%40googlegroups.com.