CVE-2026-80783

/// Technical description

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

HID: magicmouse: prevent unbounded recursion in magicmouse_raw_event()

magicmouse_raw_event() handles DOUBLE_REPORT_ID (0xf7) packets, which pack

two touch reports into one, by splitting the packet and calling itself on

each half. The only guard against runaway recursion is a "size < 1" check,

which stops zero-sized calls but does not bound the recursion depth.

A malicious HID device that matches this driver can send a report starting

with DOUBLE_REPORT_ID and filled with the sequence [0xf7, 0x00]. Each level

consumes two bytes and recurses on the remainder, so an incoming report of

up to HID_MAX_BUFFER_SIZE (16 KiB) drives roughly 8000 nested calls. That

easily exhausts the 16 KiB kernel stack, leading to a stack overflow: a

panic with CONFIG_VMAP_STACK, or memory corruption without it.

A double report only ever wraps two normal reports; it is never

legitimately nested. Refuse to re-enter the DOUBLE_REPORT_ID case

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References