Re: divide error in cdc_ncm_update_rxtx_max

From: BjÃrn Mork
Date: Tue Sep 17 2019 - 11:46:31 EST


syzbot <syzbot+ce366e2b8296e25d84f5@xxxxxxxxxxxxxxxxxxxxxxxxx> writes:

> syzbot has tested the proposed patch but the reproducer still
> triggered crash:
> divide error in usbnet_update_max_qlen
>
> cdc_ncm 5-1:1.0: setting tx_max = 16384
> divide error: 0000 [#1] SMP KASAN
> CPU: 1 PID: 1737 Comm: kworker/1:2 Not tainted 5.3.0-rc7+ #0
> Hardware name: Google Google Compute Engine/Google Compute Engine,
> BIOS Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> RIP: 0010:usbnet_update_max_qlen drivers/net/usb/usbnet.c:344 [inline]
> RIP: 0010:usbnet_update_max_qlen+0x231/0x370 drivers/net/usb/usbnet.c:338

Sure, but that's another error already fixed by Oliver..

I guess this fix worked. But I believe we should see if this is a more
generic issue than just this single driver/bug. I fear it is...



BjÃrn