Re: [PATCH v2] Fixes the null pointer deferences in nsim_bpf

[Stanislav Fomichev]

On 11/10, Jakub Kicinski wrote:
> On Fri, 10 Nov 2023 11:18:23 +0000 Dipendra Khadka wrote:
> > Syzkaller found a null pointer dereference in nsim_bpf
> > originating from the lack of a null check for state.
> > 
> > This patch fixes the issue by adding a check for state
> > in two functions nsim_prog_set_loaded() and nsim_setup_prog_hw_checks()
> > 
> > Reported-by: syzbot+44c2416196b7c607f226@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Closes: https://syzkaller.appspot.com./bug?extid=44c2416196b7c607f226
> > Fixes: 31d3ad832948 ("netdevsim: add bpf offload support")
> 
> Don't think so. It's probably due to Stan's extensions / reuse of 
> the offload infra.
> 
> Please put more effort into figuring out when and why this started
> happening. Describe your findings in the commit message.
> 
> Current patch looks too much like a bandaid.
> 
> Before you repost read:
> https://www.kernel.org/doc/html/next/process/maintainer-netdev.html

I agree, I have a similar suspicion for the same report on the bpf list [0].

0: https://lore.kernel.org/bpf/ZU13dQb2z66CJlYi@xxxxxxxxxx/