CVE-2026-64084

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

hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR

adm1266_gpio_get_multiple() iterates the PDIO portion of the

caller-supplied mask using

for_each_set_bit_from(gpio_nr, mask,

ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) {

...

}

where ADM1266_PDIO_STATUS is the PMBus command code (0xE9, i.e. 233),

not the number of PDIO pins. The intended upper bound is

ADM1266_GPIO_NR + ADM1266_PDIO_NR = 25.

gpiolib hands in a mask sized for gc.ngpio (= 25 bits on this chip),

so the iteration walks find_next_bit() up to 242, reading up to 217

extra bits (a handful of unsigned-long words: four on 64-bit, seven

on 32-bit) of whatever lives past the end of the mask in the

caller's stack. Any incidental set bit in that range then drives a

set_bit(gpio_nr, bits) call that writes past the end of the

caller-supplied bits array too -- both out-of-bounds.

Substitute ADM1266_PDIO_NR for the constant so the scan stops at the

last real PDIO bit.