RE: [PATCH] dma-direct: use the correct size for dma_set_encrypted()

From: Dexuan Cui
Date: Thu Jun 23 2022 - 03:01:07 EST


> From: Christoph Hellwig <hch@xxxxxx>
> Sent: Wednesday, June 22, 2022 10:44 PM
> To: Dexuan Cui <decui@xxxxxxxxxxxxx>
> ...
> On Wed, Jun 22, 2022 at 12:14:24PM -0700, Dexuan Cui wrote:
> > The third parameter of dma_set_encrypted() is a size in bytes rather than
> > the number of pages.
> >
> > Fixes: 4d0564785bb0 ("dma-direct: factor out dma_set_{de,en}crypted
> helpers")
> > Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
>
> see:
>
> commit 4a37f3dd9a83186cb88d44808ab35b78375082c9 (tag:
> dma-mapping-5.19-2022-05-25)
> Author: Robin Murphy <robin.murphy@xxxxxxx>
> Date: Fri May 20 18:10:13 2022 +0100
>
> dma-direct: don't over-decrypt memory

It looks like commit 4a37f3dd9a831 fixed a different issue?

Here my patch is for the latest mainline:

In dma_direct_alloc()'s error handling path, we pass 'size' to dma_set_encrypted():
out_encrypt_pages:
if (dma_set_encrypted(dev, page_address(page), size))

However, in dma_direct_free(), we pass ' 1 << page_order ' to dma_set_encrypted().
I think the ' 1 << page_order' is incorrect and it should be 'size' as well?

Thanks,
-- Dexuan