In vmw_surface_define_ioctl(), the 'num_sizes' is the sum of the
'req->mip_levels' array. This array can be assigned any value from
the user space. As both the 'num_sizes' and the array is uint32_t,
it is easy to make 'num_sizes' overflow. The later 'mip_levels' is
used as the loop count. This can lead an oob write. Add the check of
'req->mip_levels' to avoid this.
Signed-off-by: Li Qiang <liqiang6-s@xxxxxx>
---
drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index b445ce9..ef8bf83 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -713,8 +713,11 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
128;
num_sizes = 0;
- for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i)
+ for (i = 0; i < DRM_VMW_MAX_SURFACE_FACES; ++i) {
+ if (req->mip_levels[i] > DRM_VMW_MAX_MIP_LEVELS)
+ return -EINVAL;
num_sizes += req->mip_levels[i];
+ }
if (num_sizes > DRM_VMW_MAX_SURFACE_FACES *
DRM_VMW_MAX_MIP_LEVELS)
--
2.7.4
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