SB2026052845 - Use-after-free in Linux kernel vfio cdx driver

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-46036)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in vfio_cdx_set_msi_trigger() and the cdx_irqs array when handling concurrent VFIO_DEVICE_SET_IRQS ioctls. A local user can issue concurrent ioctl calls to trigger a use-after-free and cause a denial of service.

The issue occurs because one caller can observe config_msi as set while another caller clears it and frees the associated IRQ array.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/670e8864b1a218d72f08db40d0103adf38fa1d9b
• https://git.kernel.org/stable/c/7530f34ec0ca1438d45a75dcb43183a1cc92eced
• https://git.kernel.org/stable/c/7b436ade16cc81095d79b79f8efa3af0a4f5c5a2
• https://git.kernel.org/stable/c/ddf96e23c366c566283fce8377928851fa7f5e81