CVE-2026-46022
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel that allows for out-of-bounds read in the ibmasm_handle_mouse_interrupt() function. The issue occurs when the reader or writer indices exceed the allowed queue size, potentially leading to unintended reads from device registers.
Risk Assessment
This threat could lead to system crashes or unauthorized memory access, posing a risk to the integrity and availability of the system.
Recommendation
It is recommended to update the Linux kernel to a version that includes the fixes to ensure proper bounds checking of indices before use.
Original NVD description (English source)
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 mapping entirely, triggering a machine check exception. Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of the loop body, before any call to get_queue_entry(). On an out-of-range value, reset the reader register to 0 via set_queue_reader() before breaking, so that normal queue operation can resume if the corrupted hardware state is transient.