Medium [CVE-2026-80575] cs40l50-vibra - validate custom data from user space

In the Linux kernel, the following vulnerability has been resolved: Input: cs40l50-vibra - validate custom data from user space cs40l50_add() copies the custom data of an FF_PERIODIC/FF_CUSTOM effect straight from the ff_effect the user passed to EVIOCSFF, without requiring it to hold anything: work_data.custom_data = memdup_array_user(periodic->custom_data, periodic->custom_len, sizeof(s16)); work_data.custom_len = periodic->custom_len; The driver then reads two words out of that buffer: custom_data[0] as the waveform bank in cs40l50_effect_bank_set(), and custom_data[1] as the index within the bank in cs40l50_effect_index_set().

Neither read is covered by a length check, and custom_len is fully user controlled: - custom_len == 0 makes memdup_array_user() call memdup_user() with a length of zero, which returns ZERO_SIZE_PTR rather than an error, so custom_data[0] dereferences it. - custom_len == 1 allocates two bytes.

A bank of ROM or RAM keeps effect->type out of the OWT case, and custom_data[1] is then read one word past the allocation. The bank value itself is also mishandled.

The da7280 haptic driver already range checks custom_len this way. The `cs40l50-vibra` driver, responsible for haptic feedback, improperly validates the length of custom data provided by a local user.