[PATCH 0/6] drm: reject empty TTM range manager sizes

[Jiale Yao <yaojiale02@163.com>]

drm_mm_init() rejects a zero-length allocation range with a BUG check.
Several DRM TTM users can derive a zero page count from device-provided
VRAM metadata and pass it to the range manager.

This series rejects empty ranges at the affected callers and adds a
defensive check in the common range manager. Patches 1 through 4 and
6 validate the individual driver inputs. Patch 5 protects the shared
range-manager API against any remaining zero-page caller.

The series was checked with scripts/checkpatch.pl for every code patch.

Jiale Yao (6):
  drm/vram-helper: reject empty VRAM ranges
  drm/nouveau: reject empty VRAM ranges
  drm/qxl: reject empty TTM memory ranges
  drm/radeon: reject empty VRAM ranges
  drm/ttm: reject empty range manager sizes
  drm/vmwgfx: reject empty VRAM ranges

 drivers/gpu/drm/drm_gem_vram_helper.c   | 3 +++
 drivers/gpu/drm/nouveau/nouveau_ttm.c   | 3 +++
 drivers/gpu/drm/qxl/qxl_ttm.c           | 3 +++
 drivers/gpu/drm/radeon/radeon_ttm.c     | 3 +++
 drivers/gpu/drm/ttm/ttm_range_manager.c | 3 +++
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c     | 4 ++++
 6 files changed, 19 insertions(+)

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2.34.1