CVE-2026-90142

A flaw was found in the virtio_net component of the Linux kernel. When an AF_XDP (Address Family eXpress Data Path) socket is attached, the system fails to properly resize the RX (receive) ring buffer. This oversight can lead to an out-of-bounds write operation, where data is written beyond the allocated memory region. A local attacker could potentially exploit this to cause a denial of service or other memory corruption issues.

An out of bounds write can occur in virtio_net when an AF_XDP socket is attached and the RX ring is enlarged without resizing the rq xsk_buffs array. After the virtqueue grows, virtnet_rx_resume can use the new ring size and write struct xdp_buff pointers beyond the allocation created for the old ring size. The documented sequence is easily reproducible and does not require a race or a narrow timing window. Impact is at least a local denial of service through kernel memory corruption and a kernel crash. In the worst case, corruption of an adjacent kernel heap object may affect confidentiality and integrity or support privilege escalation, although reliable control of the overwritten object is not established by the supplied code. For the CVSS the PR:L is used in the paranoid score because CAP_NET_ADMIN may be delegated to a container root, network service account, or another restricted local process that does not otherwise have full control of the kernel. The issue is not directly network reachable because an attacker must locally attach an AF_XDP socket and request an RX ring resize.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.