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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 27 May 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | vfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-27T12:56:46.381Z
Reserved: 2026-05-13T15:03:33.093Z
Link: CVE-2026-46036
No data.
Status : Awaiting Analysis
Published: 2026-05-27T14:17:22.913
Modified: 2026-05-27T14:48:03.013
Link: CVE-2026-46036
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.