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Subject: Re: [PATCH][net-next] nexthop: fix incorrect allocation failure on
 nhg->spare
To:     Colin King <colin.king@canonical.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>
From:   Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Message-ID: <8b73e872-c05e-e93f-1d2d-3466da4ddbcc@cumulusnetworks.com>
Date:   Thu, 28 May 2020 17:53:21 +0300
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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>