Re: WARNING in rcu_check_gp_start_stall

[Greg KH]

On Sun, Mar 17, 2019 at 03:43:01AM -0700, syzbot wrote:
> syzbot has bisected this bug to:
> 
> commit f1e3e92135202ff3d95195393ee62808c109208c
> Author: Malcolm Priestley <tvboxspy@xxxxxxxxx>
> Date:   Wed Jul 22 18:16:42 2015 +0000
> 
>     staging: vt6655: fix tagSRxDesc -> next_desc type
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=111856cf200000
> start commit:   f1e3e921 staging: vt6655: fix tagSRxDesc -> next_desc type
> git tree:       upstream
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=131856cf200000
> console output: https://syzkaller.appspot.com/x/log.txt?x=151856cf200000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=7132344728e7ec3f
> dashboard link: https://syzkaller.appspot.com/bug?extid=111bc509cd9740d7e4aa
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16d4966cc00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10c492d0c00000
> 
> Reported-by: syzbot+111bc509cd9740d7e4aa@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: f1e3e921 ("staging: vt6655: fix tagSRxDesc -> next_desc type")

I think syzbot is a bit confused here, how can this simple patch, where
you do not have the hardware for this driver, cause this problem?

thanks,

greg k-h