On Fri, Jan 7, 2022 at 2:11 PM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> The bpf_xdp_link_update() function didn't check the program type before
> updating the program, which made it possible to install any program type as
> an XDP program, which is obviously not good. Syzbot managed to trigger this
> by swapping in an LWT program on the XDP hook which would crash in a helper
> call.
>
> Fix this by adding a check and bailing out if the types don't match.
>
> Fixes: 026a4c28e1db ("bpf, xdp: Implement LINK_UPDATE for BPF XDP link")
> Reported-by: syzbot+983941aa85af6ded1fd9@xxxxxxxxxxxxxxxxxxxxxxxxx
> Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Thanks a lot for the quick fix!
The merge window is about to begin.
We will land it as soon as possible when bpf tree will be ready
to accept fixes.
