Re: [PATCH] uprobe: avoid out-of-bounds memory access of fetching args

[maqiao . mq]

> 2024年10月14日 下午10:58，Oleg Nesterov <o...@redhat.com> 写道：
> 
> Sorry, currently I don't have time to even try to read this patch, just
> one note below...
> 
> On 10/14, Ma Qiao wrote:
>> 
>> @@ -979,6 +980,11 @@ static struct uprobe_cpu_buffer 
>> *prepare_uprobe_buffer(struct trace_uprobe *tu,
>>      ucb = uprobe_buffer_get();
>>      ucb->dsize = tu->tp.size + dsize;
>> 
>> +    if (WARN_ON_ONCE(ucb->dsize > MAX_UCB_BUFFER_SIZE)) {
>> +            ucb->dsize = MAX_UCB_BUFFER_SIZE;
>> +            dsize = MAX_UCB_BUFFER_SIZE - tu->tp.size;
>> +    }
>> +
> 
> Then you can probably kill the
> 
>       if (WARN_ON_ONCE(ucb->dsize > PAGE_SIZE))
> 
> check in __uprobe_trace_func(), no?
> 
> Oleg.

Thanks for reminder, I will remove it in v2