Copyright © 2012 Red Hat, Inc. All rights reserved. Low 2026-07-25T00:00:00 kernel: vfio: prevent infinite loop in vfio_mig_get_next_state() on blocked arc 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-835

In the Linux kernel, the following vulnerability has been resolved: vfio: prevent infinite loop in vfio_mig_get_next_state() on blocked arc vfio_mig_get_next_state() walks vfio_from_fsm_table[] one step at a time, looping to skip optional states the device does not support until *next_fsm is supported. A blocked transition is encoded as VFIO_DEVICE_STATE_ERROR, which the trailing return reports as -EINVAL. The skip loop does not account for the ERROR sentinel. state_flags_table[ERROR] is ~0U and vfio_from_fsm_table[ERROR][*] is ERROR, so once *next_fsm becomes ERROR the loop condition stays true and *next_fsm never changes. The blocked arcs STOP_COPY -> PRE_COPY and STOP_COPY -> PRE_COPY_P2P map to ERROR yet pass the support check on a precopy-capable device, causing the loop to spin forever while holding the driver state mutex. This can result in a soft lockup, and a panic with softlockup_panic set. Terminate the skip loop on the ERROR sentinel so a blocked transition falls through to the existing return and reports -EINVAL.

A flaw was found in the Linux kernel's Virtual Function I/O (VFIO) device migration feature. The `vfio_mig_get_next_state()` function, responsible for managing device migration states, contains an infinite loop. This occurs when processing certain blocked transitions, causing the system to hold a driver state mutex indefinitely. This can lead to a soft lockup of the system and potentially a kernel panic, resulting in a Denial of Service (DoS).

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-64474 https://nvd.nist.gov/vuln/detail/CVE-2026-64474 https://lore.kernel.org/linux-cve-announce/2026072546-CVE-2026-64474-a4d3@gregkh/T