Re: usb/serial/visor: slab-out-of-bounds in palm_os_3_probe

From: Andrey Konovalov
Date: Thu Oct 19 2017 - 07:19:19 EST


On Wed, Oct 4, 2017 at 4:40 PM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Oct 03, 2017 at 11:29:40AM +0200, Johan Hovold wrote:
>> On Fri, Sep 29, 2017 at 10:37:55AM +0200, Greg Kroah-Hartman wrote:
>> > On Thu, Sep 28, 2017 at 07:57:46PM +0200, Andrey Konovalov wrote:
>> > > Hi!
>> > >
>> > > I've got the following report while fuzzing the kernel with syzkaller.
>> > >
>> > > On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).
>> > >
>> > > There's no check on the connection_info->num_ports value when
>> > > iterating over ports.
>> > >
>> > > usb 1-1: Handspring Visor / Palm OS: port 162, is for unknown use
>> > > usb 1-1: Handspring Visor / Palm OS: port 81, is for unknown use
>> > > ==================================================================
>> > > BUG: KASAN: slab-out-of-bounds in palm_os_3_probe+0x4e4/0x570
>> > > Read of size 1 at addr ffff8800686daa26 by task kworker/0:1/24
>>
>> Thanks for the report, Andrey.
>>
>> > Ah, nice catch, this bug is _old_, sorry about that.
>> >
>> > The patch below should resolve this. It looks bigger than it really is,
>> > as I'm just moving the error checking higher up in the function, and
>> > loosing an indentation for when there is invalid data.
>> >
>> > Can you let me know if this solves the issue?
>>
>> And thanks for fixing this up, Greg. Will you send a proper patch that I
>> can apply?
>
> Yes, let me redo it based on your comments, and will send it out
> "correctly" in a few days.

Hi Greg,

I was going through the bugs I've reported, and it seems that you
didn't mail the patch for this one. Reminding in case you've
accidentally forgotten about it.

Thanks!

>
> thanks for the review,
>
> greg k-h