Re: [PATCH 1/2] net: lan966x: Fix potential null-ptr-deref in lan966x_stats_init()

From: Horatiu Vultur <horatiu.vultur@microchip.com>
To: Shang XiaoJing <shangxiaojing@huawei.com>
Cc: <UNGLinuxDriver@microchip.com>, <davem@davemloft.net>,
	<edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
	<lars.povlsen@microchip.com>, <Steen.Hegelund@microchip.com>,
	<daniel.machon@microchip.com>, <rmk+kernel@armlinux.org.uk>,
	<casper.casan@gmail.com>, <bjarni.jonasson@microchip.com>,
	<netdev@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/2] net: lan966x: Fix potential null-ptr-deref in lan966x_stats_init()
Date: Mon, 14 Nov 2022 15:20:17 +0100	[thread overview]
Message-ID: <20221114142017.bqaeabujh4rlxl5c@soft-dev3-1> (raw)
In-Reply-To: <20221114133853.5384-2-shangxiaojing@huawei.com>

The 11/14/2022 21:38, Shang XiaoJing wrote:
> [Some people who received this message don't often get email from shangxiaojing@huawei.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> lan966x_stats_init() calls create_singlethread_workqueue() and not
> checked the ret value, which may return NULL. And a null-ptr-deref may
> happen:
> 
> lan966x_stats_init()
>     create_singlethread_workqueue() # failed, lan966x->stats_queue is NULL
>     queue_delayed_work()
>         queue_delayed_work_on()
>             __queue_delayed_work()  # warning here, but continue
>                 __queue_work()      # access wq->flags, null-ptr-deref
> 
> Check the ret value and return -ENOMEM if it is NULL.

It looks good to me.

Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>

> 
> Fixes: 12c2d0a5b8e2 ("net: lan966x: add ethtool configuration and statistics")
> Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
> ---
>  drivers/net/ethernet/microchip/lan966x/lan966x_ethtool.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_ethtool.c b/drivers/net/ethernet/microchip/lan966x/lan966x_ethtool.c
> index e58a27fd8b50..0fb0efc224be 100644
> --- a/drivers/net/ethernet/microchip/lan966x/lan966x_ethtool.c
> +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_ethtool.c
> @@ -708,6 +708,9 @@ int lan966x_stats_init(struct lan966x *lan966x)
>         snprintf(queue_name, sizeof(queue_name), "%s-stats",
>                  dev_name(lan966x->dev));
>         lan966x->stats_queue = create_singlethread_workqueue(queue_name);
> +       if (!lan966x->stats_queue)
> +               return -ENOMEM;
> +
>         INIT_DELAYED_WORK(&lan966x->stats_work, lan966x_check_stats_work);
>         queue_delayed_work(lan966x->stats_queue, &lan966x->stats_work,
>                            LAN966X_STATS_CHECK_DELAY);
> --
> 2.17.1
> 

-- 
/Horatiu

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel