Re: [syzbot] [kernel?] general protection fault in joydev_connect

From: Aleksandr Nogikh
Date: Thu Nov 23 2023 - 04:32:43 EST


On Thu, Nov 23, 2023 at 9:55 AM gregkh@xxxxxxxxxxxxxxxxxxx
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Nov 22, 2023 at 07:55:50PM +0800, xingwei lee wrote:
> > Hi. I have reproduced this bug with repro.txt and repro.c below:
> >
> > repro.txt
> > r0 = openat$uinput(0xffffffffffffff9c, &(0x7f0000000500), 0x802, 0x0)
> > ioctl$UI_DEV_SETUP(r0, 0x405c5503, &(0x7f0000000080)={{0x0, 0xffff,
> > 0x3}, 'syz0\x00'})
> > ioctl$UI_DEV_CREATE(r0, 0x5501) (fail_nth: 51)
>
> You are using fault injection, which, by it's very name, causes faults :)

But those injected failures (that do not break the kernel, but just
emulate an error returned from a function that should be expected to
sometimes return an error) still should not lead to general protection
fault panics, shouldn't they?

--
Aleksandr

>
> Can you reproduce it without causing faults in the kernel? And if so,
> can you create a patch to fix this?
>
> thanks,
>
> greg k-h
>