Re: [PATCH linux-next] ipv4: Fix NULL deference in fnhe_remove_oldest()

From: David Ahern
Date: Thu Sep 02 2021 - 12:41:41 EST


On 9/2/21 9:38 AM, Eric Dumazet wrote:
> On Thu, Sep 2, 2021 at 9:32 AM Tim Gardner <tim.gardner@xxxxxxxxxxxxx> wrote:
>>
>> Coverity complains that linux-next commit 67d6d681e15b5 ("ipv4: make
>> exception cache less predictible") neglected to check for NULL before
>> dereferencing 'oldest'. It appears to be possible to fall through the for
>> loop without ever setting 'oldest'.
>
> Coverity is wrong.
>
> fnhe_remove_oldest() is only called when there are at least 6 items
> in the list.
>
> There is no way oldest could be NULL, or that oldest_p could contain garbage.
>

+1