drm/nouveau: do not allow negative sizes for now

The API allows up to 64-bits allocations, but size is handled as int
inside nouveau almost everywhere. Until this is fixed it's better to
prevent negative sizes.

The 256 kB before INT_MAX is paranoia, because of the large page
aligning below that could flip it above INT_MAX.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 459a44550ce5..4e7ee5f4155c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -198,6 +198,12 @@ nouveau_bo_new(struct drm_device *dev, int size, int align,
         size_t acc_size;
         int ret;
         int type = ttm_bo_type_device;
+        int max_size = INT_MAX & ~((1 << drm->client.base.vm->vmm->lpg_shift) - 1);
+
+        if (size <= 0 || size > max_size) {
+                nv_warn(drm, "skipped size %x\n", (u32)size);
+                return -EINVAL;
+        }
 
         if (sg)
                 type = ttm_bo_type_sg;