| From 5fa4e6f1c2d8c9a4e47e1931b42893172d388f2b Mon Sep 17 00:00:00 2001 |
| From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
| Date: Thu, 13 Aug 2020 09:21:09 +0300 |
| Subject: xen/gntdev: Fix dmabuf import with non-zero sgt offset |
| |
| From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
| |
| commit 5fa4e6f1c2d8c9a4e47e1931b42893172d388f2b upstream. |
| |
| 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: bf8dc55b1358 ("xen/gntdev: Implement dma-buf import functionality") |
| |
| Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
| Acked-by: Juergen Gross <jgross@suse.com> |
| Cc: <stable@vger.kernel.org> |
| Link: https://lore.kernel.org/r/20200813062113.11030-2-andr2000@gmail.com |
| Signed-off-by: Juergen Gross <jgross@suse.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/xen/gntdev-dmabuf.c | 8 ++++++++ |
| 1 file changed, 8 insertions(+) |
| |
| --- a/drivers/xen/gntdev-dmabuf.c |
| +++ b/drivers/xen/gntdev-dmabuf.c |
| @@ -613,6 +613,14 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_ |
| 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); |
