On 2023-12-15 at 10:18:26 +0100, 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>
> ---
>  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)

I tested the above fixed patch on top of v6.7-rc5 kernel.
This problem was gone, it's fixed.
Attached is the fixed dmesg log.

Tested-by: Pengfei Xu <pengfei.xu@intel.com>

Thanks!

> -- 
> 2.43.0
>