[PATCH] drm: integer overflow in vmw_surface_define_ioctl()

[xuyongjiande]

From: xuyongjian <xuyongjiande@xxxxxxxxx>

req comes from user-space, then integer overflow may happen in this line:
		num_sizes += req->mip_levels[i];

Signed-off-by: xuyongjian <xuyongjiande@xxxxxxxxx>

---
 drivers/gpu/drm/vmwgfx/vmwgfx_surface.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index 7de2ea8..5b7c7d2 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -678,8 +678,12 @@ 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_SURFACE_FACES *
+			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)
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/