From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andriin@fb.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>
Subject: Re: [PATCH] bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach
Date: Mon, 11 Jan 2021 21:03:16 +0100 [thread overview]
Message-ID: <87y2gzi6m3.fsf@toke.dk> (raw)
In-Reply-To: <20210111191650.1241578-1-jolsa@kernel.org>
Jiri Olsa <jolsa@kernel.org> writes:
> The bpf_tracing_prog_attach error path calls bpf_prog_put
> on prog, which causes refcount underflow when it's called
> from link_create function.
>
> link_create
> prog = bpf_prog_get <-- get
> ...
> tracing_bpf_link_attach(prog..
> bpf_tracing_prog_attach(prog..
> out_put_prog:
> bpf_prog_put(prog); <-- put
>
> if (ret < 0)
> bpf_prog_put(prog); <-- put
>
> Removing bpf_prog_put call from bpf_tracing_prog_attach
> and making sure its callers call it instead.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
next prev parent reply other threads:[~2021-01-11 20:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 19:16 [PATCH] bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach Jiri Olsa
2021-01-11 20:03 ` Toke Høiland-Jørgensen [this message]
2021-01-11 20:34 ` Andrii Nakryiko
2021-01-11 21:17 ` Jiri Olsa
2021-01-11 21:26 ` Andrii Nakryiko
2021-01-11 23:40 ` patchwork-bot+netdevbpf
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