{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64552", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.796Z", "datePublished": "2026-07-27T20:10:40.570Z", "dateUpdated": "2026-08-17T04:57:29.862Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:57:29.862Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio-net: fix len check in receive_big()\n\nreceive_big() bounds the device-announced length by\n(big_packets_num_skbfrags + 1) * PAGE_SIZE. That is still too loose:\nadd_recvbuf_big() sets sg[1] to start at offset\nsizeof(struct padded_vnet_hdr) into the first page, so the chain\nactually carries hdr_len + (PAGE_SIZE - sizeof(padded_vnet_hdr)) +\nbig_packets_num_skbfrags * PAGE_SIZE bytes -- 20 bytes less than the\ncheck allows for the common hdr_len == 12 case.\n\nA malicious virtio backend can announce a len in that gap. page_to_skb()\nthen walks one frag past the page chain, storing a NULL page->private\ninto skb_shinfo()->frags[MAX_SKB_FRAGS], which is both an out-of-bounds\nwrite past the static frag array and a NULL frag handed up the rx path.\n\nBound len by the size add_recvbuf_big() actually advertised." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.4, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The malicious input is the buffer length announced by the virtio backend (hypervisor, vhost-user/VDUSE daemon, or virtio-net hardware device), not data from a network peer; a conforming backend can never announce a length in the vulnerable gap. This is the local device-to-driver attack surface, matching how other malicious-virtio-device bugs are scored.\nAC:L - The backend deterministically controls feature negotiation, MTU (hence big_packets_num_skbfrags), and the announced len, so it can force big-packets mode and hit the 20-byte gap on the first packet with no race or memory-layout luck.\nPR:N - The attacking backend requires no credentials or privileges inside the victim kernel — it is outside the guest's security authority and simply completes an RX descriptor. No guest-side account is needed.\nUI:N - Triggered automatically in the NAPI receive path as soon as the backend completes a receive buffer; no victim action is required.\nS:U - The corruption and crash are confined to the kernel that owns the virtio-net driver, with no crossing into a different security-managing authority such as an IOMMU or hypervisor boundary.\nC:H - A controlled 16-byte out-of-bounds write past skb_shared_info into an adjacent skb head in the NAPI page-frag cache lets the attacker corrupt neighbouring network buffer metadata, which is leverageable to disclose adjacent kernel memory; nr_frags is also left one past MAX_SKB_FRAGS so downstream code reads out-of-bounds frag state.\nI:H - This is an out-of-bounds write past the end of the static skb_shinfo()->frags[] array with attacker-influenced index and size, corrupting adjacent slab/page-frag memory — per guidance an OOB write is High and is potentially leverageable for control-flow hijack.\nA:H - After the OOB write, a NULL page is stored as a frag and immediately dereferenced via compound_head() in softirq context, producing a guaranteed kernel oops; the backend can repeat this at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/virtio_net.c" ], "versions": [ { "version": "82f9028e83944a9eee5229cbc6fee9be1de8a62d", "lessThan": "f9451d0fd5ba635dcabb49bfe456a6db734a8986", "status": "affected", "versionType": "git" }, { "version": "946dec89c41726b94d31147ec528b96af0be1b5a", "lessThan": "38e94d63e29f4a5c6eae87ee2c02101aaa321502", "status": "affected", "versionType": "git" }, { "version": "82fe78065450d2d07f36a22e2b6b44955cf5ca5b", "lessThan": "fbeb65154583879d556ea94cb2f15888e9470f3d", "status": "affected", "versionType": "git" }, { "version": "0c716703965ffc5ef4311b65cb5d84a703784717", "lessThan": "c7fc9adf4e006155f7f2aeda052fbcde25cdcc49", "status": "affected", "versionType": "git" }, { "version": "0c716703965ffc5ef4311b65cb5d84a703784717", "lessThan": "e6b8463b7d791f3886d7584259d6e9f06a69f12e", "status": "affected", "versionType": "git" }, { "version": "0c716703965ffc5ef4311b65cb5d84a703784717", "lessThan": "9e5ad06ea826322ce8c58b4a68442a96f600c3c4", "status": "affected", "versionType": "git" }, { "version": "3e9d89f2ecd3636bd4cbdfd0b2dfdaf58f9882e2", "status": "affected", "versionType": "git" }, { "version": "6.1.159", "lessThan": "6.1.178", "status": "affected", "versionType": "semver" }, { "version": "6.6.117", "lessThan": "6.6.145", "status": "affected", "versionType": "semver" }, { "version": "6.12.58", "lessThan": "6.12.97", "status": "affected", "versionType": "semver" }, { "version": "6.17.8", "lessThan": "6.18", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/virtio_net.c" ], "versions": [ { "version": "6.18", "status": "affected" }, { "version": "0", "lessThan": "6.18", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.159", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.117", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.58", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f9451d0fd5ba635dcabb49bfe456a6db734a8986" }, { "url": "https://git.kernel.org/stable/c/38e94d63e29f4a5c6eae87ee2c02101aaa321502" }, { "url": "https://git.kernel.org/stable/c/fbeb65154583879d556ea94cb2f15888e9470f3d" }, { "url": "https://git.kernel.org/stable/c/c7fc9adf4e006155f7f2aeda052fbcde25cdcc49" }, { "url": "https://git.kernel.org/stable/c/e6b8463b7d791f3886d7584259d6e9f06a69f12e" }, { "url": "https://git.kernel.org/stable/c/9e5ad06ea826322ce8c58b4a68442a96f600c3c4" } ], "title": "virtio-net: fix len check in receive_big()", "x_generator": { "engine": "bippy-1.2.0" } } } }