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Subject: Re: [PATCH][net-next] nexthop: fix incorrect allocation failure on
 nhg->spare
To:     Nikolay Aleksandrov <nikolay@cumulusnetworks.com>,
        David Ahern <dsahern@kernel.org>,
        "David S . Miller" <davem@davemloft.net>,
        Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20200528145114.420100-1-colin.king@canonical.com>
 <8b73e872-c05e-e93f-1d2d-3466da4ddbcc@cumulusnetworks.com>
 <b0852a83-c3a5-a1be-6554-dc035e5b3d6e@cumulusnetworks.com>
From:   Colin Ian King <colin.king@canonical.com>
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Message-ID: <b9cedb4b-d1bf-fd6d-f85e-444840c3924b@canonical.com>
Date:   Thu, 28 May 2020 16:53:51 +0100
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On 28/05/2020 15:55, Nikolay Aleksandrov wrote:
> On 28/05/2020 17:53, Nikolay Aleksandrov wrote:
>> On 28/05/2020 17:51, Colin King wrote:
>>> From: Colin Ian King <colin.king@canonical.com>
>>>
>>> The allocation failure check for nhg->spare is currently checking
>>> the pointer nhg rather than nhg->spare which is never false. Fix
>>> this by checking nhg->spare instead.
>>>
>>> Addresses-Coverity: ("Logically dead code")
>>> Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
>>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>>> ---
>>>  net/ipv4/nexthop.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
>>> index ebafa5ed91ac..97423d6f2de9 100644
>>> --- a/net/ipv4/nexthop.c
>>> +++ b/net/ipv4/nexthop.c
>>> @@ -1185,7 +1185,7 @@ static struct nexthop *nexthop_create_group(struct net *net,
>>>  
>>>  	/* spare group used for removals */
>>>  	nhg->spare = nexthop_grp_alloc(num_nh);
>>> -	if (!nhg) {
>>> +	if (!nhg->spare) {
>>>  		kfree(nhg);
>>>  		kfree(nh);
>>>  		return NULL;
>>>
>>
>> Good catch, embarrassing copy paste error :-/
>> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
>>
> 
> Wait - that should be targeted at -net, that's where the fixes went.
> And the fixes tag is wrong, nhg->spare was very recently added by:
> commit 90f33bffa382
> Author: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
> Date:   Tue May 26 12:56:15 2020 -0600
> 
>     nexthops: don't modify published nexthop groups
> 

Do you require me to fix this up and re-send?

Colin