Re: [PATCH] mark pstore-blk as broken

[Al Viro]

On Tue, Jun 08, 2021 at 10:34:29AM -0700, Kees Cook wrote:
> > diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
> > index 8adabde685f1..328da35da390 100644
> > --- a/fs/pstore/Kconfig
> > +++ b/fs/pstore/Kconfig
> > @@ -173,6 +173,7 @@ config PSTORE_BLK
> >  	tristate "Log panic/oops to a block device"
> >  	depends on PSTORE
> >  	depends on BLOCK
> > +	depends on BROKEN
> >  	select PSTORE_ZONE
> >  	default n
> >  	help
> > -- 
> > 2.30.2
> > 
> 
> NAK, please answer my concerns about your patches instead:
> https://lore.kernel.org/lkml/202012011149.5650B9796@keescook/

	How about concerns about the code in question having gotten
into the kernel in the first place?  Quality aside (that's a separate
conversation, probably for tomorrow), just what happens if that thing
is triggered by the code that happens to hold a page on block device
locked?  AFAICS, __generic_file_write_iter() will cheerfully deadlock...

	Kees, may I ask you where had that thing been discussed back
then?  All I can see is linux-kernel, and that's "archived by", not
"discussed on"...