Re: NULL pointer dereference when writing fuzzed data to /dev/uhid

[Anatoly Trosinenko]

> Would you be able to share the sony.bin file?
Sent it in this message.

> Did you inject a particular device?
If you are asking me, then no, I blindly send fuzzed data with a
simple (but quite large and not very meaningful) header. That time it
just turned out to be Sony-like descriptor :)

Best regards
Anatoly

ÐÑ, 4 ÑÐÐ. 2019 Ð. Ð 19:38, Roderick Colenbrander <thunderbird2k@xxxxxxxxx>:
>
> > > For sony.bin:
> > >
> > > root@kvm-xfstests:~# cat /vtmp/sony.bin > /dev/uhid
> > > [   16.891931] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.892432] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.892894] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.893362] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.893844] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.895389] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.898165] sony 0003:054C:1000.0001: ignoring exceeding usage max
> > > [   16.901190] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.903797] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.906401] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.908957] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.911449] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.913936] sony 0003:054C:1000.0001: unknown main item tag 0x1
> > > [   16.916551] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.918454] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.919743] sony 0003:054C:1000.0001: unknown main item tag 0x4
> > > [   16.920834] sony 0003:054C:1000.0001: unknown main item tag 0xe
> > > [   16.921904] sony 0003:054C:1000.0001: unknown main item tag 0xe
> > > [   16.923006] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.924082] sony 0003:054C:1000.0001: unknown main item tag 0x2
> > > [   16.925195] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.926289] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.927400] sony 0003:054C:1000.0001: unknown main item tag 0x0
> > > [   16.928546] BUG: unable to handle kernel NULL pointer dereference
> > > at 0000000000000028
> > > [   16.929951] #PF error: [normal kernel read fault]
> > > [   16.930884] PGD 800000007a52b067 P4D 800000007a52b067 PUD 0
> > > [   16.931836] Oops: 0000 [#1] SMP PTI
> > > [   16.932437] CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted
> > > 4.20.0-xfstests-10979-g96d4f267e40 #1
> > > [   16.933752] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> > > BIOS 1.11.1-1ubuntu1 04/01/2014
> > > [   16.935372] Workqueue: events uhid_device_add_worker
> > > [   16.936321] RIP: 0010:hid_validate_values+0x48/0x110
> >
> > In a sense, it's good to have a fault there because this was added to
> > make sure we do not blindly accept any data. The fact that it doesn't
> > fail gracefully is a sign that there is something else.
> > Maybe Roderick could have a look?
> >
> > Cheers,
> > Benjamin
> >
>
> Sure I can have a look. Would you be able to share the sony.bin file?
> Did you inject a particular device? We do a lot of remapping and
> processing in hid-sony at startup. It is probably related to that.
>
> Thanks,
> Roderick

Attachment: sony.bin
Description: Binary data