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Message-ID: <998248d1-aa5f-45e0-813e-d0565fc952d3@intel.com>
Date: Wed, 14 Feb 2024 13:56:17 -0800
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH] dl2k: Fix potential NULL pointer dereference in
 receive_packet()
Content-Language: en-US
To: Rand Deeb <rand.sec96@gmail.com>, "David S . Miller"
	<davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>,
	<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC: <deeb.rand@confident.ru>, <lvc-project@linuxtesting.org>,
	<voskresenski.stanislav@confident.ru>
References: <20240213200900.41722-1-rand.sec96@gmail.com>
From: Jacob Keller <jacob.e.keller@intel.com>
In-Reply-To: <20240213200900.41722-1-rand.sec96@gmail.com>
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On 2/13/2024 12:09 PM, Rand Deeb wrote:
The subject doesn't indicate which tree for netdev it would target, but
this seems like an obvious bug fix for net.

> @@ -972,6 +972,14 @@ receive_packet (struct net_device *dev)
>  							   np->rx_buf_sz,
>  							   DMA_FROM_DEVICE);
>  			}
> +			if (skb == NULL) {
> +				np->rx_ring[entry].fraginfo = 0;
> +				printk (KERN_INFO
> +				       "%s: receive_packet: "
> +				       "Unable to re-allocate Rx skbuff.#%d\n",
> +				       dev->name, entry);

You could use netdev_warn here instead of printk, which would include
the device information. I checked a couple other drivers and none of
them appear to log any message when this fails. A handful increment a
driver count of how many allocation failures occurred. I'm not sure how
helpful this print would be in practice.

With or without changes to the printed warning message:

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>