7.8
/ 10
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
vfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex
vfio_cdx_set_msi_trigger() reads vdev->config_msi and operates on the
vdev->cdx_irqs array based on its value, but provides no serialization
against concurrent VFIO_DEVICE_SET_IRQS ioctls. Two callers can race
such that one observes config_msi as set while another clears it and
frees cdx_irqs via vfio_cdx_msi_disable(), resulting in a use-after-free
of the cdx_irqs array.
Add a cdx_irqs_lock mutex to struct vfio_cdx_device and acquire it in
vfio_cdx_set_msi_trigger(), which is the single chokepoint through
which all updates to config_msi, cdx_irqs, and msi_count flow, covering
both the ioctl path and the close-device cleanup path. This keeps the
test of config_msi atomic with the subsequent enable, disable, or
trigger operations.
Drop the pre-call !cdx_irqs test from vfio_cdx_irqs_cleanup() as part
of this change: the optimization it provided is redundant with the
!config_msi early-return inside vfio_cdx_msi_disable(), and leaving the
test in place would be an unsynchronized read of state the new lock is
meant to protect.
vfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex
vfio_cdx_set_msi_trigger() reads vdev->config_msi and operates on the
vdev->cdx_irqs array based on its value, but provides no serialization
against concurrent VFIO_DEVICE_SET_IRQS ioctls. Two callers can race
such that one observes config_msi as set while another clears it and
frees cdx_irqs via vfio_cdx_msi_disable(), resulting in a use-after-free
of the cdx_irqs array.
Add a cdx_irqs_lock mutex to struct vfio_cdx_device and acquire it in
vfio_cdx_set_msi_trigger(), which is the single chokepoint through
which all updates to config_msi, cdx_irqs, and msi_count flow, covering
both the ioctl path and the close-device cleanup path. This keeps the
test of config_msi atomic with the subsequent enable, disable, or
trigger operations.
Drop the pre-call !cdx_irqs test from vfio_cdx_irqs_cleanup() as part
of this change: the optimization it provided is redundant with the
!config_msi early-return inside vfio_cdx_msi_disable(), and leaving the
test in place would be an unsynchronized read of state the new lock is
meant to protect.
Basic Information
ID
CVE-2026-46036
Source
Linux
Published
May 27, 2026 at 12:56
Modified
May 30, 2026 at 10:46
Affected Product
Vendor
Linux
Product
Linux
Version
848e447e000c41894ff931dc7c004fd42c8840f8
Affected Versions
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 6.10
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 848e447e000c41894ff931dc7c004fd42c8840f8
Linux Linux 6.10