IT

Tracker / CVE-2026-45890

CVE-2026-45890

Medium 5.5

In the Linux kernel, the following vulnerability has been resolved: xen-netback: reject zero-queue configuration from guest A malicious or buggy Xen guest can write "0" to the xenbus key "multi-queue-num-queues". The connect() function in the backend only validates the upper bound (requested_num_queues > xenvif_max_queues) but not zero, allowing requested_num_queues=0 to reach vzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers WARN_ON_ONCE(!size) in __vmalloc_node_range(). On systems with panic_on_warn=1, this allows a guest-to-host denial of service. The Xen network interface specification requires the queue count to be "greater than zero". Add a zero check to match the validation already present in xen-blkback, which has included this guard since its multi-queue support was added.

Affected products and versions

linux linux_kernel · 3.16 → 5.10.252
linux linux_kernel · 5.11 → 5.15.202
linux linux_kernel · 5.16 → 6.1.165
linux linux_kernel · 6.13 → 6.18.14
linux linux_kernel · 6.19 → 6.19.4
linux linux_kernel · 6.2 → 6.6.128
linux linux_kernel · 6.7 → 6.12.75

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References