CVE-2026-45890
Description
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.
How to fix
- linux linux_kernel5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 3.16 ≤ v < 5.10.252, 5.11 ≤ v < 5.15.202, 5.16 ≤ v < 6.1.165, 6.2 ≤ v < 6.6.128, 6.7 ≤ v < 6.12.75, 6.13 ≤ v < 6.18.14, 6.19 ≤ v < 6.19.4 | 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4 |
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