From: Yonghong Song <yhs@fb.com>
To: Leo Yan <leo.yan@linaro.org>, Alexei Starovoitov <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
Martin Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [PATCH] bpf, libbpf: Smatch: Fix potential NULL pointer dereference
Date: Tue, 2 Jul 2019 15:34:26 +0000 [thread overview]
Message-ID: <54a834d7-6adc-c0ad-92aa-1b89e8ada79d@fb.com> (raw)
In-Reply-To: <20190702102531.23512-1-leo.yan@linaro.org>
On 7/2/19 3:25 AM, Leo Yan wrote:
> Based on the following report from Smatch, fix the potential
> NULL pointer dereference check.
>
> tools/lib/bpf/libbpf.c:3493
> bpf_prog_load_xattr() warn: variable dereferenced before check 'attr'
> (see line 3483)
>
> 3479 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
> 3480 struct bpf_object **pobj, int *prog_fd)
> 3481 {
> 3482 struct bpf_object_open_attr open_attr = {
> 3483 .file = attr->file,
> 3484 .prog_type = attr->prog_type,
> ^^^^^^
> 3485 };
>
> At the head of function, it directly access 'attr' without checking if
> it's NULL pointer. This patch moves the values assignment after
> validating 'attr' and 'attr->file'.
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Yonghong Song <yhs@fb.com>
next prev parent reply other threads:[~2019-07-02 15:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-02 10:25 [PATCH] bpf, libbpf: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-02 15:34 ` Yonghong Song [this message]
2019-07-03 10:23 ` Daniel Borkmann
2019-07-03 11:46 ` Leo Yan
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