netdev - Re: [PATCH net-next 4/6] bpf: track if the bpf program was loaded with SYS

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Date:   Thu, 27 Apr 2017 13:39:24 +0200
From:   Hannes Frederic Sowa <hannes@...essinduktion.org>
To:     Daniel Borkmann <daniel@...earbox.net>, netdev@...r.kernel.org
Cc:     ast@...nel.org, daniel@...earbox.com, jbenc@...hat.com,
        aconole@...heb.org
Subject: Re: [PATCH net-next 4/6] bpf: track if the bpf program was loaded
 with SYS_ADMIN capabilities

On 26.04.2017 23:04, Daniel Borkmann wrote:
> On 04/26/2017 08:24 PM, Hannes Frederic Sowa wrote:
>> diff --git a/net/core/filter.c b/net/core/filter.c
>> index 9a37860a80fc78..dc020d40bb770a 100644
>> --- a/net/core/filter.c
>> +++ b/net/core/filter.c
>> @@ -1100,7 +1100,7 @@ int bpf_prog_create(struct bpf_prog **pfp,
>> struct sock_fprog_kern *fprog)
>>       if (!bpf_check_basics_ok(fprog->filter, fprog->len))
>>           return -EINVAL;
>>
>> -    fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0);
>> +    fp = bpf_prog_alloc(bpf_prog_size(fprog->len), 0, false);
>>       if (!fp)
>>           return -ENOMEM;
>>
> 
> Did you check that transferring allow_ptr_leaks doesn't have a side
> effect on the nfp JIT? I believe it can also do cbpf migrations to
> a certain extend.

Initially I grepped allow_ptr_leaks usages and didn't see it. I just
looked through the code path and didn't see how it could have an impact.
Also, cbpf programs shouldn't depend on allow_ptr_leak to the best of my
knowledge, no?

Thanks,
Hannes