{"id":"CVE-2026-97994","state":"PUBLISHED","title":"vhost/vdpa: reject VRING_NUM larger than device max","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost/vdpa: reject VRING_NUM larger than device max\n\nvhost_vring_set_num() accepts any non-zero power-of-two queue size that\nfits in 16 bits. vhost-vdpa then passes that value to set_vq_num()\nwithout comparing it with get_vq_num_max().\n\nA process with access to /dev/vhost-vdpa-* can therefore configure a\nqueue larger than the device advertises. With vdpa_sim, the worker can\nwalk descriptors beyond the mapped descriptor ring. KASAN reports a\n16-byte out-of-bounds read, corresponding to one vring_desc, in the\nvringh IOTLB path:\n\n  BUG: KASAN: out-of-bounds in _copy_from_iter\n  Read of size 16\n  copy_from_iotlb\n  copydesc_iotlb\n  vringh_getdesc_iotlb\n  vdpasim_net_work\n\nCache get_vq_num_max() immediately after reset. Some backends derive\nit from writable queue-size state, so querying it after SET_NUM may\nreturn the current size instead of the device capability. Invalidate\nthe cached value before reset so a failed reset leaves SET_NUM\ndisabled.\n\nFor VHOST_SET_VRING_NUM, copy the complete vring state once and use\nthe same index and size for validation, vq->num, and set_vq_num().\nThis ensures that validation and use operate on the same copied values.","publishedAt":"2026-09-25T10:23:25.719Z","updatedAt":"2026-10-19T09:12:01.173Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"4875c65ca53797a0a402fe2bb54d1b12f28b3cda","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"68232102f20fc961327fb9e0f605a7eaadf030a9","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"59522639a7d71cff4e20d594d0b9ea30dd0c77e0","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"ccb1dc7c527f8c925925cf92afc76ae590dac311","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vdpa.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vdpa.c"]}],"references":["https://git.kernel.org/stable/c/4875c65ca53797a0a402fe2bb54d1b12f28b3cda","https://git.kernel.org/stable/c/1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4","https://git.kernel.org/stable/c/68232102f20fc961327fb9e0f605a7eaadf030a9","https://git.kernel.org/stable/c/59522639a7d71cff4e20d594d0b9ea30dd0c77e0","https://git.kernel.org/stable/c/ccb1dc7c527f8c925925cf92afc76ae590dac311"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97994.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97994","state":"PUBLISHED","datePublished":"2026-09-25T10:23:25.719Z","dateUpdated":"2026-10-19T09:12:01.173Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:18:58.209Z"},"containers":{"cna":{"title":"vhost/vdpa: reject VRING_NUM larger than device max","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost/vdpa: reject VRING_NUM larger than device max\n\nvhost_vring_set_num() accepts any non-zero power-of-two queue size that\nfits in 16 bits. vhost-vdpa then passes that value to set_vq_num()\nwithout comparing it with get_vq_num_max().\n\nA process with access to /dev/vhost-vdpa-* can therefore configure a\nqueue larger than the device advertises. With vdpa_sim, the worker can\nwalk descriptors beyond the mapped descriptor ring. KASAN reports a\n16-byte out-of-bounds read, corresponding to one vring_desc, in the\nvringh IOTLB path:\n\n  BUG: KASAN: out-of-bounds in _copy_from_iter\n  Read of size 16\n  copy_from_iotlb\n  copydesc_iotlb\n  vringh_getdesc_iotlb\n  vdpasim_net_work\n\nCache get_vq_num_max() immediately after reset. Some backends derive\nit from writable queue-size state, so querying it after SET_NUM may\nreturn the current size instead of the device capability. Invalidate\nthe cached value before reset so a failed reset leaves SET_NUM\ndisabled.\n\nFor VHOST_SET_VRING_NUM, copy the complete vring state once and use\nthe same index and size for validation, vq->num, and set_vq_num().\nThis ensures that validation and use operate on the same copied values."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"4875c65ca53797a0a402fe2bb54d1b12f28b3cda","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"68232102f20fc961327fb9e0f605a7eaadf030a9","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"59522639a7d71cff4e20d594d0b9ea30dd0c77e0","versionType":"git"},{"version":"4c8cf31885f69e86be0b5b9e6677a26797365e1d","status":"affected","lessThan":"ccb1dc7c527f8c925925cf92afc76ae590dac311","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vdpa.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/vhost/vdpa.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4875c65ca53797a0a402fe2bb54d1b12f28b3cda"},{"url":"https://git.kernel.org/stable/c/1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4"},{"url":"https://git.kernel.org/stable/c/68232102f20fc961327fb9e0f605a7eaadf030a9"},{"url":"https://git.kernel.org/stable/c/59522639a7d71cff4e20d594d0b9ea30dd0c77e0"},{"url":"https://git.kernel.org/stable/c/ccb1dc7c527f8c925925cf92afc76ae590dac311"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:12:01.173Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}