From: Daniel Borkmann <daniel@iogearbox.net>
To: Gaurav Singh <gaurav1086@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
KP Singh <kpsingh@chromium.org>,
"open list:XDP (eXpress Data Path)" <netdev@vger.kernel.org>,
"open list:XDP (eXpress Data Path)" <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] xdp_rxq_info_user: Add null check after malloc
Date: Thu, 11 Jun 2020 16:12:51 +0200 [thread overview]
Message-ID: <de636159-a33e-cfa9-0d8f-e9c81873588f@iogearbox.net> (raw)
In-Reply-To: <20200610030145.17263-1-gaurav1086@gmail.com>
On 6/10/20 5:01 AM, Gaurav Singh wrote:
> Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
>
> The memset call is made right after malloc call which
> can return a NULL pointer upon failure causing a
> segmentation fault. Fix this by adding a null check
> right after malloc() and then do memset().
The SoB should come after the commit message here.
> ---
> samples/bpf/xdp_rxq_info_user.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c
> index 4fe47502ebed..2d03c84a4cca 100644
> --- a/samples/bpf/xdp_rxq_info_user.c
> +++ b/samples/bpf/xdp_rxq_info_user.c
> @@ -202,11 +202,11 @@ static struct datarec *alloc_record_per_cpu(void)
>
> size = sizeof(struct datarec) * nr_cpus;
> array = malloc(size);
> - memset(array, 0, size);
All these below are candidates for calloc(), can we just use that instead and
simplify the below.
> if (!array) {
> fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
> exit(EXIT_FAIL_MEM);
> }
> + memset(array, 0, size);
> return array;
> }
>
> @@ -218,11 +218,11 @@ static struct record *alloc_record_per_rxq(void)
>
> size = sizeof(struct record) * nr_rxqs;
> array = malloc(size);
> - memset(array, 0, size);
> if (!array) {
> fprintf(stderr, "Mem alloc error (nr_rxqs:%u)\n", nr_rxqs);
> exit(EXIT_FAIL_MEM);
> }
> + memset(array, 0, size);
> return array;
> }
>
> @@ -233,11 +233,11 @@ static struct stats_record *alloc_stats_record(void)
> int i;
>
> rec = malloc(sizeof(*rec));
> - memset(rec, 0, sizeof(*rec));
> if (!rec) {
> fprintf(stderr, "Mem alloc error\n");
> exit(EXIT_FAIL_MEM);
> }
> + memset(rec, 0, sizeof(*rec));
> rec->rxq = alloc_record_per_rxq();
> for (i = 0; i < nr_rxqs; i++)
> rec->rxq[i].cpu = alloc_record_per_cpu();
>
Thanks,
Daniel
prev parent reply other threads:[~2020-06-11 14:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 3:01 [PATCH] xdp_rxq_info_user: Add null check after malloc Gaurav Singh
2020-06-11 14:12 ` Daniel Borkmann [this message]
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