Re: [PATCH] bpf: Replace BUG_ON when fp_old is NULL

[Aditya Pakki]

On 12/16/19 5:17 AM, Daniel Borkmann wrote:
> On 12/15/19 11:08 PM, Yonghong Song wrote:
>> On 12/15/19 7:44 AM, Aditya Pakki wrote:
>>> If fp_old is NULL in bpf_prog_realloc, the program does an assertion
>>> and crashes. However, we can continue execution by returning NULL to
>>> the upper callers. The patch fixes this issue.
>>
>> Could you share how to reproduce the assertion and crash? I would
>> like to understand the problem first before making changes in the code.
>> Thanks!
> 
> Fully agree, Aditya, please elaborate if you have seen a crash!

Thanks for your responses Alexei and Daniel. We identified this issue via static analysis
and have not seen a crash. However, by looking at the callers of bpf_prog_realloc, I do 
agree that fp_old is never NULL. 

Would you recommend removing the BUG_ON assertion altogether ?