On Thu, May 21, 2020 at 8:21 AM <sdf@xxxxxxxxxx> wrote:
>
> On 05/21, Jakub Sitnicki wrote:
> > When attaching a flow dissector program to a network namespace with
> > bpf(BPF_PROG_ATTACH, ...) we grab a reference to bpf_prog.
>
> > If netns gets destroyed while a flow dissector is still attached, and
> > there
> > are no other references to the prog, we leak the reference and the program
> > remains loaded.
>
> > Leak can be reproduced by running flow dissector tests from selftests/bpf:
>
> > # bpftool prog list
> > # ./test_flow_dissector.sh
> > ...
> > selftests: test_flow_dissector [PASS]
> > # bpftool prog list
> > 4: flow_dissector name _dissect tag e314084d332a5338 gpl
> > loaded_at 2020-05-20T18:50:53+0200 uid 0
> > xlated 552B jited 355B memlock 4096B map_ids 3,4
> > btf_id 4
> > #
>
> > Fix it by detaching the flow dissector program when netns is going away.
>
> > Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook")
> > Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
> Reviewed-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Applied. Thanks
