Re: [PATCH net] bpf: fix allocation warnings in bpf maps and integer overflow

[Dmitry Vyukov]

On Mon, Nov 30, 2015 at 3:13 PM, Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
> On 11/30/2015 02:57 PM, Dmitry Vyukov wrote:
> ...
>>
>> kamlloc produces a WARNING if you try to allocate more than it ever
>> possibly can (KMALLOC_SHIFT_MAX).
>
>
> Sure, I understand that.
>
> The kzalloc() in array_map_alloc() is however with __GFP_NOWARN flag
> already.
> The warning only triggers in mm if:
>
>   WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
>
> Your test case is using ca.map_type = 1, which is BPF_MAP_TYPE_HASH. So on
> update you're triggering the kmalloc() in htab_map_update_elem().
>
> I'm just asking about the added change in array map.


Then, sorry.
Let's wait for Alexei.
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