On Sat, Jan 8, 2022 at 11:37 AM Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
>
> 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.
Applied to bpf tree.
