From: fuyufan fuyufan@huawei.com

we get (Unable to handle kernel NULL pointer dereference at virtual address 000000000000000c) when call drm_property_blob_put(). After analysis, we get the following process:

alloc faild: drm_atomic_set_mode_for_crtc()     drm_property_create_blob() // failed     state->mode_blob = ERR_PTR(-ENOMEM)

free illegal pointer: __drm_atomic_helper_crtc_destroy_state()     drm_property_blob_put(state->mode_blob)             drm_mode_object_put(&blob->base);   // here blob is ERR_PTR(-ENOMEM)

So do we have to determine if blob is an error code before calling drm_mode_object_put().

Signed-off-by: fuyufan fuyufan@huawei.com ---  drivers/gpu/drm/drm_property.c | 2 +-  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c index 69dfed57c..05dba22fe 100644 --- a/drivers/gpu/drm/drm_property.c +++ b/drivers/gpu/drm/drm_property.c @@ -597,7 +597,7 @@ EXPORT_SYMBOL(drm_property_create_blob);   */  void drm_property_blob_put(struct drm_property_blob *blob)  { -       if (!blob) +       if (IS_ERR_OR_NULL(blob))                 return;

drm_mode_object_put(&blob->base); -- 2.23.0