Commit 5fa4e6f1 authored by Oleksandr Andrushchenko's avatar Oleksandr Andrushchenko Committed by Juergen Gross
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xen/gntdev: Fix dmabuf import with non-zero sgt offset 



It is possible that the scatter-gather table during dmabuf import has
non-zero offset of the data, but user-space doesn't expect that.
Fix this by failing the import, so user-space doesn't access wrong data.

Fixes: bf8dc55b ("xen/gntdev: Implement dma-buf import functionality")

Signed-off-by: default avatarOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Acked-by: default avatarJuergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200813062113.11030-2-andr2000@gmail.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent f2e39e8c

drivers/xen/gntdev-dmabuf.c

+8 −0
Original line number Diff line number Diff line
@@ -613,6 +613,14 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct device *dev, 
		goto fail_detach;

	}



	/* Check that we have zero offset. */

	if (sgt->sgl->offset) {

		ret = ERR_PTR(-EINVAL);

		pr_debug("DMA buffer has %d bytes offset, user-space expects 0\n",

			 sgt->sgl->offset);

		goto fail_unmap;

	}



	/* Check number of pages that imported buffer has. */

	if (attach->dmabuf->size != gntdev_dmabuf->nr_pages << PAGE_SHIFT) {

		ret = ERR_PTR(-EINVAL);