From: John Fastabend <john.fastabend@gmail.com>
To: Qing Wang <wangqing@vivo.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
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>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Qing Wang <wangqing@vivo.com>
Subject: RE: [PATCH V2] net: bpf: switch over to memdup_user()
Date: Mon, 18 Oct 2021 09:26:49 -0700 [thread overview]
Message-ID: <616da04982886_1eb12083d@john-XPS-13-9370.notmuch> (raw)
In-Reply-To: <1634556651-38702-1-git-send-email-wangqing@vivo.com>
Qing Wang wrote:
> This patch fixes the following Coccinelle warning:
>
> net/bpf/test_run.c:361:8-15: WARNING opportunity for memdup_user
> net/bpf/test_run.c:1055:8-15: WARNING opportunity for memdup_user
>
> Use memdup_user rather than duplicating its implementation
> This is a little bit restricted to reduce false positives
>
> Signed-off-by: Qing Wang <wangqing@vivo.com>
> ---
> net/bpf/test_run.c | 21 ++++++---------------
> 1 file changed, 6 insertions(+), 15 deletions(-)
LGTM, but subject line should be '[PATCH bpf-next v2]' there is no reason
to push to fixes trees here.
Also might be worth noting that the original kzalloc could have just been
a kalloc because copy_from_user will zero any extra bytes.
Acked-by: John Fastabend <john.fastabend@gmail.com>
>
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index 5296087..fbda8f5
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -358,13 +358,9 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog,
> return -EINVAL;
>
> if (ctx_size_in) {
> - info.ctx = kzalloc(ctx_size_in, GFP_USER);
> - if (!info.ctx)
> - return -ENOMEM;
> - if (copy_from_user(info.ctx, ctx_in, ctx_size_in)) {
> - err = -EFAULT;
> - goto out;
> - }
> + info.ctx = memdup_user(ctx_in, ctx_size_in);
> + if (IS_ERR(info.ctx))
> + return PTR_ERR(info.ctx);
> } else {
> info.ctx = NULL;
> }
> @@ -392,7 +388,6 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog,
> copy_to_user(&uattr->test.retval, &info.retval, sizeof(u32)))
> err = -EFAULT;
>
> -out:
> kfree(info.ctx);
> return err;
> }
> @@ -1052,13 +1047,9 @@ int bpf_prog_test_run_syscall(struct bpf_prog *prog,
> return -EINVAL;
>
> if (ctx_size_in) {
> - ctx = kzalloc(ctx_size_in, GFP_USER);
> - if (!ctx)
> - return -ENOMEM;
> - if (copy_from_user(ctx, ctx_in, ctx_size_in)) {
> - err = -EFAULT;
> - goto out;
> - }
> + ctx = memdup_user(ctx_in, ctx_size_in);
> + if (IS_ERR(ctx))
> + return PTR_ERR(ctx);
> }
>
> rcu_read_lock_trace();
> --
> 2.7.4
>
prev parent reply other threads:[~2021-10-18 16:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-18 11:30 [PATCH V2] net: bpf: switch over to memdup_user() Qing Wang
2021-10-18 16:26 ` John Fastabend [this message]
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