Hi Thomas, url: https://github.com/0day-ci/linux/commits/Thomas-Zimmermann/Default-to-cac... base: c34f157421f6905e6b4a79a312e9175dce2bc607 config: arm64-randconfig-m031-20201111 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; smatch warnings: drivers/gpu/drm/drm_gem_shmem_helper.c:59 __drm_gem_shmem_create() error: potentially dereferencing uninitialized 'shmem'. vim +/shmem +59 drivers/gpu/drm/drm_gem_shmem_helper.c 7d2cd72a9aa3df3 Daniel Vetter 2020-05-29 38 static struct drm_gem_shmem_object * 7d2cd72a9aa3df3 Daniel Vetter 2020-05-29 39 __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private) 2194a63a818db71 Noralf Trønnes 2019-03-12 40 { 2194a63a818db71 Noralf Trønnes 2019-03-12 41 struct drm_gem_shmem_object *shmem; ^^^^^ 2194a63a818db71 Noralf Trønnes 2019-03-12 42 struct drm_gem_object *obj; 7d2cd72a9aa3df3 Daniel Vetter 2020-05-29 43 int ret = 0; 2194a63a818db71 Noralf Trønnes 2019-03-12 44 2194a63a818db71 Noralf Trønnes 2019-03-12 45 size = PAGE_ALIGN(size); 2194a63a818db71 Noralf Trønnes 2019-03-12 46 2194a63a818db71 Noralf Trønnes 2019-03-12 47 if (dev->driver->gem_create_object) 2194a63a818db71 Noralf Trønnes 2019-03-12 48 obj = dev->driver->gem_create_object(dev, size); 2194a63a818db71 Noralf Trønnes 2019-03-12 49 else 2194a63a818db71 Noralf Trønnes 2019-03-12 50 obj = kzalloc(sizeof(*shmem), GFP_KERNEL); 2194a63a818db71 Noralf Trønnes 2019-03-12 51 if (!obj) 2194a63a818db71 Noralf Trønnes 2019-03-12 52 return ERR_PTR(-ENOMEM); 2194a63a818db71 Noralf Trønnes 2019-03-12 53 2194a63a818db71 Noralf Trønnes 2019-03-12 54 if (!obj->funcs) 2194a63a818db71 Noralf Trønnes 2019-03-12 55 obj->funcs = &drm_gem_shmem_funcs; 2194a63a818db71 Noralf Trønnes 2019-03-12 56 6c0af452d25888d Thomas Zimmermann 2020-11-06 57 if (private) { 7d2cd72a9aa3df3 Daniel Vetter 2020-05-29 58 drm_gem_private_object_init(dev, obj, size); 6c0af452d25888d Thomas Zimmermann 2020-11-06 @59 shmem->map_wc = false; /* dma-buf mappings use always writecombine */ ^^^^^^^^^^^^^^^^^^^^^ Not initialized until later 6c0af452d25888d Thomas Zimmermann 2020-11-06 60 } else { 2194a63a818db71 Noralf Trønnes 2019-03-12 61 ret = drm_gem_object_init(dev, obj, size); 6c0af452d25888d Thomas Zimmermann 2020-11-06 62 } 2194a63a818db71 Noralf Trønnes 2019-03-12 63 if (ret) 2194a63a818db71 Noralf Trønnes 2019-03-12 64 goto err_free; 2194a63a818db71 Noralf Trønnes 2019-03-12 65 2194a63a818db71 Noralf Trønnes 2019-03-12 66 ret = drm_gem_create_mmap_offset(obj); 2194a63a818db71 Noralf Trønnes 2019-03-12 67 if (ret) 2194a63a818db71 Noralf Trønnes 2019-03-12 68 goto err_release; 2194a63a818db71 Noralf Trønnes 2019-03-12 69 2194a63a818db71 Noralf Trønnes 2019-03-12 70 shmem = to_drm_gem_shmem_obj(obj); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2194a63a818db71 Noralf Trønnes 2019-03-12 71 mutex_init(&shmem->pages_lock); 2194a63a818db71 Noralf Trønnes 2019-03-12 72 mutex_init(&shmem->vmap_lock); 17acb9f35ed736c Rob Herring 2019-08-05 73 INIT_LIST_HEAD(&shmem->madv_list); --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org