Re: [PATCH bpf] bpf: Add missing BPF_LINK_TYPE invocations

[Hou Tao <houtao@huaweicloud.com>]

On 12/15/2023 5:18 PM, Jiri Olsa wrote:
> Pengfei Xu reported [1] Syzkaller/KASAN issue found in bpf_link_show_fdinfo.
>
> The reason is missing BPF_LINK_TYPE invocation for uprobe multi
> link and for several other links, adding that.
>
> [1] https://lore.kernel.org/bpf/ZXptoKRSLspnk2ie@xpf.sh.intel.com/
>
> Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link")
> Fixes: e420bed02507 ("bpf: Add fd-based tcx multi-prog infra with link support")
> Fixes: 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs")
> Fixes: 35dfaad7188c ("netkit, bpf: Add bpf programmable net device")
> Reported-by: Pengfei Xu <pengfei.xu@intel.com>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---

Some BPF_LINK_TYPE() definitions below can be guarded by CONFIG_xx
macro, but I think it doesn't matter here, because these definitions are
only used in bpf_link_type_strs(), so

Acked-by: Hou Tao <houtao1@huawei.com>

>  include/linux/bpf_types.h | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
> index fc0d6f32c687..38cbdaec6bdf 100644
> --- a/include/linux/bpf_types.h
> +++ b/include/linux/bpf_types.h
> @@ -148,3 +148,7 @@ BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf)
>  #endif
>  BPF_LINK_TYPE(BPF_LINK_TYPE_KPROBE_MULTI, kprobe_multi)
>  BPF_LINK_TYPE(BPF_LINK_TYPE_STRUCT_OPS, struct_ops)
> +BPF_LINK_TYPE(BPF_LINK_TYPE_NETFILTER, netfilter)
> +BPF_LINK_TYPE(BPF_LINK_TYPE_TCX, tcx)
> +BPF_LINK_TYPE(BPF_LINK_TYPE_UPROBE_MULTI, uprobe_multi)
> +BPF_LINK_TYPE(BPF_LINK_TYPE_NETKIT, netkit)