{"id":"CVE-2026-45890","state":"PUBLISHED","title":"xen-netback: reject zero-queue configuration from guest","description":"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 > 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.","publishedAt":"2026-05-27T12:17:01.466Z","updatedAt":"2026-05-27T12:17:01.466Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"2993e0f904c45f8af12917344bb1cac7ccd05a60","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"787bfa423228c4b02ba3368128f625d579085353","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"ce66d6786de45b7ed9cbbdc0988054bf09e58f54","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"88b0fced1bbbfdb356a007592604008ffc93a6a1","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"ec4859ac5c933e3315543a61adc1ca4358006a41","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"654780dee9eae419e1648ea58462c4efe54518fa","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"d99f69ddc70fd9f4b8148add62209a1a8eb5c615","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"6d1dc8014334c7fb25719999bca84d811e60a559","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/xen-netback/xenbus.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.16","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/xen-netback/xenbus.c"]}],"references":["https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60","https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353","https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54","https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1","https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41","https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa","https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615","https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45890.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45890","state":"PUBLISHED","datePublished":"2026-05-27T12:17:01.466Z","dateUpdated":"2026-05-27T12:17:01.466Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.083Z"},"containers":{"cna":{"title":"xen-netback: reject zero-queue configuration from guest","descriptions":[{"lang":"en","value":"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 > 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"2993e0f904c45f8af12917344bb1cac7ccd05a60","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"787bfa423228c4b02ba3368128f625d579085353","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"ce66d6786de45b7ed9cbbdc0988054bf09e58f54","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"88b0fced1bbbfdb356a007592604008ffc93a6a1","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"ec4859ac5c933e3315543a61adc1ca4358006a41","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"654780dee9eae419e1648ea58462c4efe54518fa","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"d99f69ddc70fd9f4b8148add62209a1a8eb5c615","versionType":"git"},{"version":"8d3d53b3e43363e79ab9a9ecc149b06c1314b25d","status":"affected","lessThan":"6d1dc8014334c7fb25719999bca84d811e60a559","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/xen-netback/xenbus.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.16","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/xen-netback/xenbus.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2993e0f904c45f8af12917344bb1cac7ccd05a60"},{"url":"https://git.kernel.org/stable/c/787bfa423228c4b02ba3368128f625d579085353"},{"url":"https://git.kernel.org/stable/c/ce66d6786de45b7ed9cbbdc0988054bf09e58f54"},{"url":"https://git.kernel.org/stable/c/88b0fced1bbbfdb356a007592604008ffc93a6a1"},{"url":"https://git.kernel.org/stable/c/ec4859ac5c933e3315543a61adc1ca4358006a41"},{"url":"https://git.kernel.org/stable/c/654780dee9eae419e1648ea58462c4efe54518fa"},{"url":"https://git.kernel.org/stable/c/d99f69ddc70fd9f4b8148add62209a1a8eb5c615"},{"url":"https://git.kernel.org/stable/c/6d1dc8014334c7fb25719999bca84d811e60a559"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-27T12:17:01.466Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.10.252"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}