Message-ID: <21a41a1c-4ae4-47c7-c608-b6dd82758b16@molgen.mpg.de>
Date:   Wed, 25 Jan 2023 21:09:39 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.7.1
Subject: Re: [Intel-wired-lan] [PATCH] i40e: Add checking for null for
 nlmsg_find_attr()
To:     Natalia Petrova <n.petrova@fintech.ru>
Cc:     Jesse Brandeburg <jesse.brandeburg@intel.com>,
        lvc-project@linuxtesting.org, intel-wired-lan@lists.osuosl.org,
        linux-kernel@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        netdev@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "David S. Miller" <davem@davemloft.net>
References: <20230125141328.8479-1-n.petrova@fintech.ru>
Content-Language: en-US
From:   Paul Menzel <pmenzel@molgen.mpg.de>
In-Reply-To: <20230125141328.8479-1-n.petrova@fintech.ru>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

Dear Natalia,


Thank you for your patch.

Am 25.01.23 um 15:13 schrieb Natalia Petrova:

In the commit message summary, you could use:

Check if nlmsg_find_attr() returns null

> The result of nlmsg_find_attr() 'br_spec' is dereferenced in
> nla_for_each_nested, but it can take null value in 'nla_find' finction,

f*u*nction

> which will result in an error.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops")
> Signed-off-by: Natalia Petrova <n.petrova@fintech.ru>
> ---
>   drivers/net/ethernet/intel/i40e/i40e_main.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
> index b36bf9c3e1e4..ed4be4ffeb09 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
> @@ -13101,6 +13101,8 @@ static int i40e_ndo_bridge_setlink(struct net_device *dev,
>   	}
>   
>   	br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
> +	if (!br_spec)
> +		return -ENOENT;
>   
>   	nla_for_each_nested(attr, br_spec, rem) {
>   		__u16 mode;


Kind regards,

Paul