Re: WARNING in can_rcv

[Marc Kleine-Budde]

On 01/16/2018 06:58 PM, syzbot wrote:
> Hello,
> 
> syzkaller hit the following crash on  
> a8750ddca918032d6349adbf9a4b6555e7db20da
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
> 
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+4386709c0c1284dca827@xxxxxxxxxxxxxxxxxxxxxxxxx
> It will help syzbot understand when the bug is fixed. See footer for  
> details.
> If you forward the report, please keep this part and the footer.
> 
> device eql entered promiscuous mode
> ------------[ cut here ]------------
> PF_CAN: dropped non conform CAN skbuf: dev type 65534, len 42, datalen 0
> WARNING: CPU: 0 PID: 3650 at net/can/af_can.c:729 can_rcv+0x1c5/0x200  
> net/can/af_can.c:724
> Kernel panic - not syncing: panic_on_warn set ...

Invalid packages generate a warning (WARN_ONCE()), and you have
panic_on_warn active. Should we better silently drop these CAN packages?

Marc

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