drm/vmwgfx: Limit display layout ioctl array size to VMWGFX_NUM_DISPLAY_UNITS

[ Upstream commit 28a5dfd4f615539fb22fb6d5c219c199c14e6eb6 ]

Currently the array size is only limited by the largest kmalloc size which
is incorrect. This change will also return a more specific error message
than ENOMEM to userspace.

Signed-off-by: Ian Forbes <ian.forbes@broadcom.com>
Reviewed-by: Zack Rusin <zack.rusin@broadcom.com>
Reviewed-by: Martin Krastev <martin.krastev@broadcom.com>
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240808200634.1074083-1-ian.forbes@broadcom.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index ac3d7ff3f5bb9f93b98fa2a8002f67706a5fe16b..def98d868deb49ae441539f3644086f1ae430a39 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -61,7 +61,7 @@
 #define VMWGFX_DRIVER_MINOR 20
 #define VMWGFX_DRIVER_PATCHLEVEL 0
 #define VMWGFX_FIFO_STATIC_SIZE (1024*1024)
-#define VMWGFX_MAX_DISPLAYS 16
+#define VMWGFX_NUM_DISPLAY_UNITS 8
 #define VMWGFX_CMD_BOUNCE_INIT_SIZE 32768
 
 #define VMWGFX_MIN_INITIAL_WIDTH 1280
@@ -81,7 +81,7 @@
 #define VMWGFX_NUM_GB_CONTEXT 256
 #define VMWGFX_NUM_GB_SHADER 20000
 #define VMWGFX_NUM_GB_SURFACE 32768
-#define VMWGFX_NUM_GB_SCREEN_TARGET VMWGFX_MAX_DISPLAYS
+#define VMWGFX_NUM_GB_SCREEN_TARGET VMWGFX_NUM_DISPLAY_UNITS
 #define VMWGFX_NUM_DXCONTEXT 256
 #define VMWGFX_NUM_DXQUERY 512
 #define VMWGFX_NUM_MOB (VMWGFX_NUM_GB_CONTEXT +\

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 11f7c0e5420e047f10fc740ac936c2d683a91665..33f73d559be72d3dbe0c9e3bbc22299821829878 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -2327,7 +2327,7 @@ int vmw_kms_update_layout_ioctl(struct drm_device *dev, void *data,
        struct drm_mode_config *mode_config = &dev->mode_config;
        struct drm_vmw_update_layout_arg *arg =
                (struct drm_vmw_update_layout_arg *)data;
-       void __user *user_rects;
+       const void __user *user_rects;
        struct drm_vmw_rect *rects;
        struct drm_rect *drm_rects;
        unsigned rects_size;
@@ -2339,6 +2339,8 @@ int vmw_kms_update_layout_ioctl(struct drm_device *dev, void *data,
                                            VMWGFX_MIN_INITIAL_HEIGHT};
                vmw_du_update_layout(dev_priv, 1, &def_rect);
                return 0;
+       } else if (arg->num_outputs > VMWGFX_NUM_DISPLAY_UNITS) {
+               return -E2BIG;
        }
 
        rects_size = arg->num_outputs * sizeof(struct drm_vmw_rect);

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
index 19a843da87b789b62279ecb9dccb8b2ddb19fe2f..ec86f92517a148c15831f1ac2e1aa40958de837b 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
@@ -198,9 +198,6 @@ struct vmw_kms_dirty {
        s32 unit_y2;
 };
 
-#define VMWGFX_NUM_DISPLAY_UNITS 8
-
-
 #define vmw_framebuffer_to_vfb(x) \
        container_of(x, struct vmw_framebuffer, base)
 #define vmw_framebuffer_to_vfbs(x) \