drm/nouveau/mem: guard against NULL pointer access in mem_del

other drivers seems to do something similar

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Cc: Dave Airlie <airlied@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201006220528.13925-2-kherbst@redhat.com

diff --git a/drivers/gpu/drm/nouveau/nouveau_mem.c b/drivers/gpu/drm/nouveau/nouveau_mem.c
index b1bb542..e5fae57 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_mem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_mem.c
@@ -176,6 +176,8 @@ void
 nouveau_mem_del(struct ttm_mem_reg *reg)
 {
        struct nouveau_mem *mem = nouveau_mem(reg);
+       if (!mem)
+               return;
        nouveau_mem_fini(mem);
        kfree(reg->mm_node);
        reg->mm_node = NULL;