In the Linux kernel, the following vulnerability has been resolved: spi: Fix simplification of devm_spi_register_controller This reverts commit 59ebbe40fb51 ("spi: simplify devm_spi_register_controller"). If devm_add_action() fails in devm_add_action_or_reset(), devm_spi_unregister() will be called, it decreases the refcount of 'ctlr->dev' to 0, then it will cause uaf in the drivers that calling spi_put_controller() in error path.