CVE-2026-89587

Status: UPDATED  |  Advisory ID: CVE-2026-89587

Key Details

Affected Products, Subsystems & Sectors

What to Know

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

ACPI: pfr_update: fix stack buffer overflow in query_capability()

query_capability() copies four ACPI buffer objects returned by the

firmware _DSM into fixed-size u8[16] fields in struct

pfru_update_cap_info using memcpy with the firmware-supplied length:

memcpy(&cap_hdr->code_type,

elements[CAP_CODE_TYPE_IDX].buffer.pointer,

elements[CAP_CODE_TYPE_IDX].buffer.length);

The same pattern repeats for drv_type, platform_id, and oem_id.

If the firmware returns buffer.length > 16 for any of these fields,

memcpy writes past the destination array.

struct pfru_update_cap_info is stack-allocated in pfru_ioctl().

Confirmed with KASAN on 7.2-rc6: three stack-out-of-bounds reports

are generated when a DSM returns 64-byte buffers, with writes reaching

44 bytes past the end of cap_hdr's [64, 156) frame window into

adjacent stack redzones.

Introduce a helper pointer to out_obj->package.elements and use it

to validate each buffer length against its destination field size

before copying, returning -EINVAL if the firmware supplies an

oversized buffer. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References