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Date:   Tue, 18 Apr 2023 14:46:33 -0600
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Subject: Re: [PATCH net-next v2] net/ipv6: silence 'passing zero to ERR_PTR()'
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To:     Jakub Kicinski <kuba@kernel.org>, Dan Carpenter <error27@gmail.com>
Cc:     Haoyi Liu <iccccc@hust.edu.cn>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        hust-os-kernel-patches@googlegroups.com, yalongz@hust.edu.cn,
        Dongliang Mu <dzm91@hust.edu.cn>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230413101005.7504-1-iccccc@hust.edu.cn>
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From:   David Ahern <dsahern@kernel.org>
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On 4/17/23 8:17 PM, Jakub Kicinski wrote:
> On Fri, 14 Apr 2023 09:32:51 +0300 Dan Carpenter wrote:
>> Also it can return NULL.
>>
>> net/xfrm/xfrm_policy.c
>>   3229                  dst = dst_orig;
>>   3230          }
>>   3231  ok:
>>   3232          xfrm_pols_put(pols, drop_pols);
>>   3233          if (dst && dst->xfrm &&
>>                     ^^^
>> "dst" is NULL.
> 
> Don't take my word for it, but AFAICT it's impossible to get there with
> dst == NULL. I think we can remove this check instead if that's what
> makes smatch infer that dst may be NULL.
> 

That was my conclusion as well staring at it multiple times, but given
the horrible maze of goto's I cannot definitively say that.