CVE-2026-89585

In the Linux kernel, the following vulnerability has been resolved:

auxdisplay: charlcd: cancel backlight work on registration failure

With CONFIG_CHARLCD_BL_FLASH, charlcd_init() schedules bl_work before charlcd_register() calls misc_register(). If registration fails, the caller frees the charlcd object while delayed work still contains its address.

Add charlcd_deinit() to cancel the delayed work and turn the backlight off. Use it for both registration rollback and normal unregistration.