linux-kernel - Re: [PATCH net-next v29 3/3] mctp pcc: Implement MCTP over PCC Transport

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aNagUmU8GOMbpfGq@horms.kernel.org>
Date: Fri, 26 Sep 2025 15:16:50 +0100
From: Simon Horman <horms@...nel.org>
To: Adam Young <admiyo@...amperecomputing.com>
Cc: Jeremy Kerr <jk@...econstruct.com.au>,
	Matt Johnston <matt@...econstruct.com.au>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Sudeep Holla <sudeep.holla@....com>,
	Jonathan Cameron <Jonathan.Cameron@...wei.com>,
	Huisong Li <lihuisong@...wei.com>
Subject: Re: [PATCH net-next v29 3/3] mctp pcc: Implement MCTP over PCC
 Transport

On Thu, Sep 25, 2025 at 03:00:26PM -0400, Adam Young wrote:

...

> +static int initialize_MTU(struct net_device *ndev)
> +{
> +	struct mctp_pcc_ndev *mctp_pcc_ndev = netdev_priv(ndev);
> +	struct mctp_pcc_mailbox *outbox;
> +	int mctp_pcc_mtu;
> +
> +	outbox = &mctp_pcc_ndev->outbox;
> +	outbox->chan = pcc_mbox_request_channel(&outbox->client, outbox->index);
> +	mctp_pcc_mtu = outbox->chan->shmem_size - sizeof(struct pcc_header);

Hi Adam,

On the line below it is expected that outbox->chan may be an error value
rather than a valid pointer. But on the line above outbox->chan is
dereferenced.

This does not seem consistent.

Flagged by Smatch.

> +	if (IS_ERR(outbox->chan))
> +		return PTR_ERR(outbox->chan);
> +
> +	pcc_mbox_free_channel(mctp_pcc_ndev->outbox.chan);
> +
> +	mctp_pcc_ndev = netdev_priv(ndev);
> +	ndev->mtu = MCTP_MIN_MTU;
> +	ndev->max_mtu = mctp_pcc_mtu;
> +	ndev->min_mtu = MCTP_MIN_MTU;
> +
> +	return 0;
> +}

...

-- 
pw-bot: changes-requested