Re: Re: [PATCH] filemap: Init the newly allocated folio memory to 0 for the filemap
From: Lizhi Xu
Date: Thu Aug 01 2024 - 01:29:16 EST
> > syzbot report KMSAN: uninit-value in pick_link, this is because the
> > corresponding folio was not found from the mapping, and the memory was
> > not initialized when allocating a new folio for the filemap.
> >
> > To avoid the occurrence of kmsan report uninit-value, initialize the
> > newly allocated folio memory to 0.
>
> NAK.
>
> You are papering over the real bug here.
Did you see the splat? I think you didn't see that.
>
> That page either
> * has been returned by find_get_page(), cached, uptodate and
> with uninitialized contents or
> * has been returned by successful read_mapping_page() - and
> left with uninitialized contents or
> * had inode->i_size in excess of initialized contents.
>
> I'd suggest bisecting that.