Re: [PATCH] Revert "mtd: spinand: Fix OOB read"

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hello,

Greg KH <gregkh@linuxfoundation.org> wrote on Tue, 5 Jan 2021 11:31:26
+0100:

> On Tue, Jan 05, 2021 at 11:18:21AM +0100, Felix Fietkau wrote:
> > This reverts stable commit baad618d078c857f99cc286ea249e9629159901f.
> > 
> > This commit is adding lines to spinand_write_to_cache_op, wheras the upstream
> > commit 868cbe2a6dcee451bd8f87cbbb2a73cf463b57e5 that this was supposed to
> > backport was touching spinand_read_from_cache_op.
> > It causes a crash on writing OOB data by attempting to write to read-only
> > kernel memory.
> > 
> > Cc: Miquel Raynal <miquel.raynal@bootlin.com>
> > Signed-off-by: Felix Fietkau <nbd@nbd.name>
> > ---
> >  drivers/mtd/nand/spi/core.c | 4 ----
> >  1 file changed, 4 deletions(-)  
> 
> So the backport to 5.10.y broke, but not the backport to 4.19.y or
> 5.4.y?  Can you provide a "correct" backport for this instead of just
> removing this fix?

Agreed, I think the proper way to handle the situation would be to move
these three lines to spinand_read_from_cache_op() instead of just
getting rid of them.

Thanks,
Miquèl