CVE-2026-46022

Technical Description

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

misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()

ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read

when the queue reader or writer index from hardware exceeds

REMOTE_QUEUE_SIZE (60).

A compromised service processor can trigger this by writing an

out-of-range value to the reader or writer MMIO register before

asserting an interrupt. Since writer is re-read from hardware on

every loop iteration, it can also be set to an out-of-range value

after the loop has already started.

The root cause is that get_queue_reader() and get_queue_writer() return

raw readl() values that are passed directly into get_queue_entry(),

which computes:

queue_begin + reader * sizeof(struct remote_input)

with no bounds check. This unchecked MMIO address is then passed to

memcpy_fromio(), reading 8 bytes from unintended device registers.

For sufficiently large values the address falls outside the PCI BAR

m

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References