Re: [PATCH v6 bpf 0/4] lwt: fix return values of BPF ops

From: Yan Zhai
Date: Fri Aug 18 2023 - 12:02:24 EST


On Fri, Aug 18, 2023 at 9:55 AM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
>
> On 8/18/23 4:58 AM, Yan Zhai wrote:
> > lwt xmit hook does not expect positive return values in function
> > ip_finish_output2 and ip6_finish_output. However, BPF programs can
> > directly return positive statuses such like NET_XMIT_DROP, NET_RX_DROP,
> > and etc to the caller. Such return values would make the kernel continue
> > processing already freed skbs and eventually panic.
> >
> > This set fixes the return values from BPF ops to unexpected continue
> > processing, checks strictly on the correct continue condition for
> > future proof. In addition, add missing selftests for BPF redirect
> > and reroute cases for BPF-CI.
> >
> > v5: https://lore.kernel.org/bpf/cover.1692153515.git.yan@xxxxxxxxxxxxxx/
> > v4: https://lore.kernel.org/bpf/ZMD1sFTW8SFiex+x@debian.debian/T/
> > v3: https://lore.kernel.org/bpf/cover.1690255889.git.yan@xxxxxxxxxxxxxx/
> > v2: https://lore.kernel.org/netdev/ZLdY6JkWRccunvu0@debian.debian/
> > v1: https://lore.kernel.org/bpf/ZLbYdpWC8zt9EJtq@debian.debian/
> >
> > changes since v5:
> > * fix BPF-CI failures due to missing config and busybox ping issue
>
> Series looks good, thanks! Given we're fairly close to merge window and
> this has been broken for quite some time, I took this into bpf-next.
>
Thanks Daniel! Can you also queue this up for stable (or guide how I can do it)?

Yan


> Thanks,
> Daniel