SB20260727113 - NULL pointer dereference in Linux kernel virtio driver

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-64457)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 6.8 [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]

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

The vulnerability exists due to a NULL pointer dereference in virtio_pci queue handling in vp_del_vqs() when unbinding a virtio balloon device with conditional queue entries absent. A local user can write to the virtio_balloon unbind sysfs interface to cause a denial of service.

The issue occurs when optional stats, free_page, or reporting queues are not present, creating holes in the queue info array and causing a mismatch between sparse and dense queue indexing.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/075bc3c779e1ea7294afabdcb7e0a49536959b28
• https://git.kernel.org/stable/c/41e6dc1a10036c9f47057033f19af7e52ec464b6
• https://git.kernel.org/stable/c/64a4c0befa77bcc01076aec9f93863ffd4ed06b7
• https://git.kernel.org/stable/c/f7d380fb525c13bdd114369a1979c80c346e6abc