On Tue, Aug 2, 2022 at 6:57 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> We need to release possible hash from trampoline fops object
> before removing it, otherwise we leak it.
>
> Fixes: 00963a2e75a8 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Great catch! Thanks!
Acked-by: Song Liu <song@xxxxxxxxxx>
> ---
> kernel/bpf/trampoline.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
> index 0f532e6a717f..ff87e38af8a7 100644
> --- a/kernel/bpf/trampoline.c
> +++ b/kernel/bpf/trampoline.c
> @@ -841,7 +841,10 @@ void bpf_trampoline_put(struct bpf_trampoline *tr)
> * multiple rcu callbacks.
> */
> hlist_del(&tr->hlist);
> - kfree(tr->fops);
> + if (tr->fops) {
> + ftrace_free_filter(tr->fops);
> + kfree(tr->fops);
> + }
> kfree(tr);
> out:
> mutex_unlock(&trampoline_mutex);
> --
> 2.37.1
>
