Bug 2502550 (CVE-2026-64084) - CVE-2026-64084 kernel: hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR
Summary: CVE-2026-64084 kernel: hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple a...
Keywords:
Status: NEW
Alias: CVE-2026-64084
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-19 17:05 UTC by OSIDB Bzimport
Modified: 2026-07-20 13:16 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-07-19 17:05:37 UTC
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.


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