{"id":"CVE-2026-97994","title":"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","summary":"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 tha…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4c8cf31885f69e86be0b5b9e6677a26797365e1d < 1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4","Linux >= 4c8cf31885f69e86be0b5b9e6677a26797365e1d < 68232102f20fc961327fb9e0f605a7eaadf030a9","Linux >= 4c8cf31885f69e86be0b5b9e6677a26797365e1d < 59522639a7d71cff4e20d594d0b9ea30dd0c77e0","Linux >= 4c8cf31885f69e86be0b5b9e6677a26797365e1d < ccb1dc7c527f8c925925cf92afc76ae590dac311","Linux 5.7"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:27.637","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97994","references":[{"url":"https://git.kernel.org/stable/c/1d09201d81b7d3e276860cc7b7dbf6c6cbe8e9b4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/59522639a7d71cff4e20d594d0b9ea30dd0c77e0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/68232102f20fc961327fb9e0f605a7eaadf030a9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ccb1dc7c527f8c925925cf92afc76ae590dac311","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.864Z","slug":"CVE-2026-97994","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}