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From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date:   Wed, 20 Jan 2021 11:23:27 -0800
Message-ID: <CAADnVQJr0idctwt53eD3dFmbZ_upLT6_7jc4raD825aPi640sA@mail.gmail.com>
Subject: Re: [PATCH] bpf: put file handler if no storage found
To:     Pan Bian <bianpan2016@163.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@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@kernel.org>,
        Network Development <netdev@vger.kernel.org>,
        bpf <bpf@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>
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On Tue, Jan 19, 2021 at 4:03 AM Pan Bian <bianpan2016@163.com> wrote:
>
> Put file f if inode_storage_ptr() returns NULL.
>
> Signed-off-by: Pan Bian <bianpan2016@163.com>
> ---
>  kernel/bpf/bpf_inode_storage.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
> index 6edff97ad594..089d5071d4fc 100644
> --- a/kernel/bpf/bpf_inode_storage.c
> +++ b/kernel/bpf/bpf_inode_storage.c
> @@ -125,8 +125,12 @@ static int bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key,
>
>         fd = *(int *)key;
>         f = fget_raw(fd);
> -       if (!f || !inode_storage_ptr(f->f_inode))
> +       if (!f)
> +               return -EBADF;
> +       if (!inode_storage_ptr(f->f_inode)) {
> +               fput(f);
>                 return -EBADF;
> +       }

Good catch.
Somehow the patch is not in patchwork.
Could you please resubmit with Fixes tag and reduce cc list?
I guess it's hitting some spam filters in vger.