Re: Re: [PATCH] x86/microcode/amd: Add __list_del_entry_valid() in front of __list_del() in free_cache()

From: Jiasheng Jiang
Date: Fri Oct 08 2021 - 03:12:35 EST


On Tue, Sep 28, 2021 at 22:29:19PM +0000, Christoph Hellwig wrote:
>On Tue, Sep 28, 2021 at 09:04:44AM +0000, Jiasheng Jiang wrote:
>> Directly use __list_del() to remove 'p->plist' might be unsafe,
>> as we can see from the __list_del_entry_valid() of 'lib/list_debug.c'
>> that p->plist->prev or p->plist->next may be the LIST_POISON,
>> or p->list is not a valid double list.
>> In that case, __list_del() will be corruption.
>> Therefore, we suggest that __list_del_entry_valid()
>> should be added in front of the __list_del() in free_cache.

>No one should be using list_del directly anyway, so please fix that.

What the 'fix that' means?