From: Song Liu <song@kernel.org>
To: He Fengqing <hefengqing@huawei.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>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [bpf-next 1/3] bpf: Move bpf_prog_clone_free into filter.h file
Date: Wed, 7 Jul 2021 00:02:52 -0700 [thread overview]
Message-ID: <CAPhsuW4RNWsOH5-NDiOF5RNgejsadrkqUbqN9Mh+fxWHQZOCMQ@mail.gmail.com> (raw)
In-Reply-To: <20210707043811.5349-2-hefengqing@huawei.com>
On Tue, Jul 6, 2021 at 8:53 PM He Fengqing <hefengqing@huawei.com> wrote:
>
> Move bpf_prog_clone_free function into filter.h, so we can use
> it in other file.
>
> Signed-off-by: He Fengqing <hefengqing@huawei.com>
> ---
> include/linux/filter.h | 15 +++++++++++++++
> kernel/bpf/core.c | 20 +-------------------
> 2 files changed, 16 insertions(+), 19 deletions(-)
>
> diff --git a/include/linux/filter.h b/include/linux/filter.h
> index 472f97074da0..f39e008a377d 100644
> --- a/include/linux/filter.h
> +++ b/include/linux/filter.h
> @@ -884,6 +884,21 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
> gfp_t gfp_extra_flags);
> void __bpf_prog_free(struct bpf_prog *fp);
>
> +static inline void bpf_prog_clone_free(struct bpf_prog *fp)
> +{
> + /* aux was stolen by the other clone, so we cannot free
> + * it from this path! It will be freed eventually by the
> + * other program on release.
> + *
> + * At this point, we don't need a deferred release since
> + * clone is guaranteed to not be locked.
> + */
> + fp->aux = NULL;
> + fp->stats = NULL;
> + fp->active = NULL;
> + __bpf_prog_free(fp);
> +}
> +
> static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
> {
> __bpf_prog_free(fp);
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 034ad93a1ad7..49b0311f48c1 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -238,10 +238,7 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
> /* We keep fp->aux from fp_old around in the new
> * reallocated structure.
> */
After the change, we can remove the comment above.
> - fp_old->aux = NULL;
> - fp_old->stats = NULL;
> - fp_old->active = NULL;
> - __bpf_prog_free(fp_old);
> + bpf_prog_clone_free(fp_old);
Please add a couple sentences in the commit log about this chanage.
Thanks,
Song
next prev parent reply other threads:[~2021-07-07 7:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 4:38 [bpf-next 0/3] potential memleak and use after free in bpf verifier He Fengqing
2021-07-07 4:38 ` [bpf-next 1/3] bpf: Move bpf_prog_clone_free into filter.h file He Fengqing
2021-07-07 7:02 ` Song Liu [this message]
2021-07-07 4:38 ` [bpf-next 2/3] bpf: Fix a memory leak in an error handling path in 'bpf_patch_insn_data()' He Fengqing
2021-07-07 4:38 ` [bpf-next 3/3] bpf: Fix a use after free in bpf_check() He Fengqing
2021-07-07 7:25 ` Song Liu
2021-07-08 3:00 ` He Fengqing
2021-07-08 3:09 ` Alexei Starovoitov
2021-07-09 11:11 ` He Fengqing
2021-07-09 15:12 ` Alexei Starovoitov
2021-07-12 2:17 ` He Fengqing
2021-07-13 23:17 ` Alexei Starovoitov
2021-07-14 1:53 ` He Fengqing
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