Re: [PATCH 5.10 1/1] i40e: Add checking for null for nlmsg_find_attr()

[Jesse Brandeburg <jesse.brandeburg@intel.com>]

On 1/26/2023 11:55 AM, Jesse Brandeburg wrote:
> On 1/26/2023 5:55 AM, Natalia Petrova wrote:
>> The result of nlmsg_find_attr() 'br_spec' is dereferenced in
>> nla_for_each_nested(), but it can take null value in nla_find() function,
>> 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 53d0083e35da..4626d2a1af91 100644
>> --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
>> +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
>> @@ -13167,6 +13167,8 @@ 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 -EINVAL;
>>       nla_for_each_nested(attr, br_spec, rem) {
>>           __u16 mode;
> 
> Makes sense to me. Thanks.
> 
> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
> 

I presume that you meant this to be targeted to the "net" tree, which 
you should indicate with the subject line:
[PATCH net ...]

as per the netdev rules published [1], and generally you don't need a 
cover letter for a single patch.

[1] https://www.kernel.org/doc/html/v5.10/networking/netdev-FAQ.html