Re: Add Morton,Peter and David for discussion//Re: [PATCH -next] uprobes: fix two zero old_folio bugs in __replace_page()

[Tong Tiangen <tongtiangen@huawei.com>]

在 2025/2/20 16:38, David Hildenbrand 写道:
> On 20.02.25 03:31, Tong Tiangen wrote:
>>
>>
>> 在 2025/2/20 0:12, David Hildenbrand 写道:
>>> On 19.02.25 16:22, Oleg Nesterov wrote:
>>>> On 02/18, Tong Tiangen wrote:
>>>>>
>>>>> OK, Before your rewrite last merged, How about i change the 
>>>>> solution to
>>>>> just reject them immediately after get_user_page_vma_remote()？
>>>>
>>>> I agree, uprobe_write_opcode() should simply fail if
>>>> is_zero_page(old_page).
>>>
>>> Yes. That's currently only syzkaller that triggers it, not some sane use
>>> case.
>>
>> OK, change as follows:
>>
>> --- a/kernel/events/uprobes.c
>> +++ b/kernel/events/uprobes.c
>> @@ -506,6 +506,12 @@ int uprobe_write_opcode(struct arch_uprobe
>> *auprobe, struct mm_struct *mm,
>>           if (ret <= 0)
>>                   goto put_old;
>>
>> +       if (WARN(is_zero_page(old_page),
> 
> This can likely be triggered by user space, so do not use WARN.

OK,thanks.

Hi Oleg, is that all right?

Thanks,
Tong.

>