drm/vmwgfx: Make sure user-space can't DMA across buffer object boundaries v2

commit cbd75e97a5 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@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Hellstrom
2014-04-15 18:25:48 +02:00
committed by Greg Kroah-Hartman
parent 900bbb9d90
commit f8df1b4619

View File

@@ -1214,14 +1214,36 @@ 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);