{"id":"CVE-2026-45890","summary":"xen-netback: reject zero-queue configuration from guest","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxen-netback: reject zero-queue configuration from guest\n\nA malicious or buggy Xen guest can write \"0\" to the xenbus key\n\"multi-queue-num-queues\". The connect() function in the backend only\nvalidates the upper bound (requested_num_queues \u003e xenvif_max_queues)\nbut not zero, allowing requested_num_queues=0 to reach\nvzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers\nWARN_ON_ONCE(!size) in __vmalloc_node_range().\n\nOn systems with panic_on_warn=1, this allows a guest-to-host denial\nof service.\n\nThe Xen network interface specification requires\nthe queue count to be \"greater than zero\".\n\nAdd a zero check to match the validation already present\nin xen-blkback, which has included this\nguard since its multi-queue support was added.","modified":"2026-06-27T11:55:07.790384633Z","published":"2026-05-27T12:17:01.466Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45890.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60"},{"type":"WEB","url":"https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"},{"type":"WEB","url":"https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45890.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45890"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d"},{"fixed":"2993e0f904c45f8af12917344bb1cac7ccd05a60"},{"fixed":"787bfa423228c4b02ba3368128f625d579085353"},{"fixed":"ce66d6786de45b7ed9cbbdc0988054bf09e58f54"},{"fixed":"88b0fced1bbbfdb356a007592604008ffc93a6a1"},{"fixed":"ec4859ac5c933e3315543a61adc1ca4358006a41"},{"fixed":"654780dee9eae419e1648ea58462c4efe54518fa"},{"fixed":"d99f69ddc70fd9f4b8148add62209a1a8eb5c615"},{"fixed":"6d1dc8014334c7fb25719999bca84d811e60a559"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-45890.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.16.0"},{"fixed":"5.10.252"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.202"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.165"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.128"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.14"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-45890.json"}}],"schema_version":"1.7.5"}