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 callers 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.

Affected Software

References

• https://git.kernel.org/stable/c/17cee2f59029039416e8f6303050038eb59ba149
• https://git.kernel.org/stable/c/299efd14c2eda7e5fd40025e54addd4151a01081
• https://git.kernel.org/stable/c/2aef8f08c479f4cbc83e1e6b19d1c94d4dd24f17
• https://git.kernel.org/stable/c/4d1da9a6be5a8156c532d571c2ed237169f99244
• https://git.kernel.org/stable/c/b96c7f0bc0713dc6403912f6527d4ff9168d6fe6
• https://git.kernel.org/stable/c/d0593e15fdeb56048a72c5c6e720f702759d0ccd
• https://git.kernel.org/stable/c/d7834d92251baade796812876e95555e2066fa9f
• https://git.kernel.org/stable/c/fa7ca363069a70b0d1aa51e8892e3095fe2ac1ec