From: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.
===============
commit cbd75e97a525e3819c02dc18bc2d67aa544c9e45 upstream.
We already check that the buffer object we're accessing is registered with
the file. Now also make sure that we can't DMA across buffer object boundaries.
v2: Code commenting update.
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Reviewed-by: Jakob Bornecrantz <jakob@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 8b059eb09d9b..1b9aa982257e 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -834,14 +834,36 @@ static int vmw_cmd_dma(struct vmw_private *dev_priv,
SVGA3dCmdSurfaceDMA dma;
} *cmd;
int ret;
+ SVGA3dCmdSurfaceDMASuffix *suffix;
+ uint32_t bo_size;
cmd = container_of(header, struct vmw_dma_cmd, header);
+ suffix = (SVGA3dCmdSurfaceDMASuffix *)((unsigned long) &cmd->dma +
+ header->size - sizeof(*suffix));
+
+ /* Make sure device and verifier stays in sync. */
+ if (unlikely(suffix->suffixSize != sizeof(*suffix))) {
+ DRM_ERROR("Invalid DMA suffix size.\n");
+ return -EINVAL;
+ }
+
ret = vmw_translate_guest_ptr(dev_priv, sw_context,
&cmd->dma.guest.ptr,
&vmw_bo);
if (unlikely(ret != 0))
return ret;
+ /* Make sure DMA doesn't cross BO boundaries. */
+ bo_size = vmw_bo->base.num_pages * PAGE_SIZE;
+ if (unlikely(cmd->dma.guest.ptr.offset > bo_size)) {
+ DRM_ERROR("Invalid DMA offset.\n");
+ return -EINVAL;
+ }
+
+ bo_size -= cmd->dma.guest.ptr.offset;
+ if (unlikely(suffix->maximumOffset > bo_size))
+ suffix->maximumOffset = bo_size;
+
ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
user_surface_converter, &cmd->dma.host.sid,
NULL);
--
1.9.3
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