[PATCH] drm: cast calculation to __u64 to fix potential integer overflow

[Gax-c]

From: Zichen Xie <zichenxie0...@gmail.com>

Like commit b0b0d811eac6 ("drm/mediatek: Fix coverity issue with
unintentional integer overflow"), directly multiply pitch and
height may lead to integer overflow. Add a cast to avoid it.

Fixes: 6d1782919dc9 ("drm/cma: Introduce drm_gem_cma_dumb_create_internal()")
Fixes: dc5698e80cf7 ("Add virtio gpu driver.")
Fixes: dc6057ecb39e ("drm/tegra: gem: dumb: pitch and size are outputs")
Signed-off-by: Zichen Xie <zichenxie0...@gmail.com>
Cc: sta...@vger.kernel.org
---
 drivers/gpu/drm/drm_gem_dma_helper.c | 6 +++---
 drivers/gpu/drm/tegra/gem.c          | 2 +-
 drivers/gpu/drm/virtio/virtgpu_gem.c | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_dma_helper.c 
b/drivers/gpu/drm/drm_gem_dma_helper.c
index 870b90b78bc4..020c3b17fc02 100644
--- a/drivers/gpu/drm/drm_gem_dma_helper.c
+++ b/drivers/gpu/drm/drm_gem_dma_helper.c
@@ -272,8 +272,8 @@ int drm_gem_dma_dumb_create_internal(struct drm_file 
*file_priv,
        if (args->pitch < min_pitch)
                args->pitch = min_pitch;
 
-       if (args->size < args->pitch * args->height)
-               args->size = args->pitch * args->height;
+       if (args->size < (__u64)args->pitch * args->height)
+               args->size = (__u64)args->pitch * args->height;
 
        dma_obj = drm_gem_dma_create_with_handle(file_priv, drm, args->size,
                                                 &args->handle);
@@ -306,7 +306,7 @@ int drm_gem_dma_dumb_create(struct drm_file *file_priv,
        struct drm_gem_dma_object *dma_obj;
 
        args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
-       args->size = args->pitch * args->height;
+       args->size = (__u64)args->pitch * args->height;
 
        dma_obj = drm_gem_dma_create_with_handle(file_priv, drm, args->size,
                                                 &args->handle);
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index d275404ad0e9..a84acdbbbe3f 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -548,7 +548,7 @@ int tegra_bo_dumb_create(struct drm_file *file, struct 
drm_device *drm,
        struct tegra_bo *bo;
 
        args->pitch = round_up(min_pitch, tegra->pitch_align);
-       args->size = args->pitch * args->height;
+       args->size = (__u64)args->pitch * args->height;
 
        bo = tegra_bo_create_with_handle(file, drm, args->size, 0,
                                         &args->handle);
diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c 
b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 7db48d17ee3a..d5407316b12e 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -72,7 +72,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
                return -EINVAL;
 
        pitch = args->width * 4;
-       args->size = pitch * args->height;
+       args->size = (__u64)pitch * args->height;
        args->size = ALIGN(args->size, PAGE_SIZE);
 
        params.format = virtio_gpu_translate_format(DRM_FORMAT_HOST_XRGB8888);
-- 
2.34.1