CVE-2026-45890

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60	Patch
https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa	Patch
https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559	Patch
https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353	Patch
https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1	Patch
https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54	Patch
https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615	Patch
https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

History

No history.

Information

Published : 2026-05-27 14:17

Updated : 2026-06-25 21:13

NVD link : CVE-2026-45890

Mitre link : CVE-2026-45890

CVE.ORG link : CVE-2026-45890

JSON object : View

Products Affected

linux

linux_kernel

CWE

NVD-CWE-noinfo

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