CVE-2026-64474
🔶 mediumSummary
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
Description
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.