{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80615", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.774Z", "datePublished": "2026-08-28T06:48:36.315Z", "dateUpdated": "2026-10-16T19:26:30.819Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-29T06:21:24.054Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dst_metadata: fix false-positive memcpy overflow in tun_dst_unclone\n\nkmalloc_flex() in metadata_dst_alloc() sets __counted_by for the\nstructure to the options_len, which is then initialized to zero.\nLater, we're initializing the structure by copying the tunnel info\ntogether with the options, and this triggers a warning for a potential\nmemcpy overflow, since the compiler estimates that the options can't\nfit into the structure, even though the memory for them is actually\nallocated.\n\n memcpy: detected buffer overflow: 104 byte write of buffer size 96\n WARNING: CPU: X PID: Y at lib/string_helpers.c:1036 __fortify_report\n skb_tunnel_info_unclone+0x179/0x190\n geneve_xmit+0x7fe/0xe00\n\nThe issue is triggered when built with clang and source fortification.\n\nFix that by doing the copy in two stages: first - the main data with\nthe options_len, then the options. This way the correct length should\nbe known at the time of the copy.\n\nIt would be better if the options_len never changed after allocation,\nbut the allocation code is a little separate from the initialization\nand it would be awkward and potentially dangerous to return a struct\nwith options_len set to a non-zero value from the metadata_dst_alloc().\n\nAnother option would be to use ip_tunnel_info_opts_set(), but it is\ndoing too many unnecessary operations for the use case here." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "baseScore": 8.2, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is reached from geneve_xmit/vxlan_xmit and OVS dev_fill_metadata_dst during overlay packet transmit; remote peers can inject Geneve/VXLAN UDP traffic with tunnel options that later traverse skb_tunnel_info_unclone() on cloud, Kubernetes, and OpenStack/OVN nodes.\nAC:L - On kernels built with CONFIG_FORTIFY_SOURCE and clang, a remote attacker can deterministically trigger the fortified memcpy check by sending Geneve/VXLAN packets carrying non-zero tunnel options that provoke PMTU handling or OVS egress-metadata cloning; no races or victim-specific memory layout are required.\nPR:N - Exploitation requires only that the target host already runs Geneve/VXLAN/OVS overlay netdevs, which is routine in data centers; remote overlay peers and unauthenticated senders whose packets are forwarded through these tunnels need no elevated privileges on the target system.\nUI:N - The fortify warning is triggered automatically during kernel packet transmit or OVS metadata handling with no action required from a local user or administrator beyond normal network operation on an overlay-enabled host.\nS:U - Impact is a kernel fortify WARN/BUG in the host networking stack during tunnel metadata cloning; it does not cross VM, container, or IOMMU security boundaries into another authority domain.\nC:L - No actual out-of-bounds read occurs because fortify halts the memcpy before any real overflow, but __fortify_report() emits a kernel warning and call trace that can disclose limited kernel text/layout information useful for further exploitation.\nI:N - This is a fortify false positive: metadata_dst_alloc() correctly sizes the destination via kmalloc_flex() and fortify aborts before the memcpy executes; there is no memory corruption, arbitrary write, or code-execution primitive.\nA:H - Triggering the fortify check calls __fortify_panic(), which issues WARN then BUG(), causing a kernel oops/panic and immediate denial of service on overlay hosts processing malicious Geneve/VXLAN tunnel-metadata traffic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/dst_metadata.h" ], "versions": [ { "version": "69050f8d6d075dc01af7a5f2f550a8067510366f", "lessThan": "7ce31739fe88a558370135db95bbeec1e7ddfc29", "status": "affected", "versionType": "git" }, { "version": "69050f8d6d075dc01af7a5f2f550a8067510366f", "lessThan": "4c6d43db2a4d2cef3921e885cf34798f790d34ea", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/dst_metadata.h" ], "versions": [ { "version": "7.0", "status": "affected" }, { "version": "0", "lessThan": "7.0", "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": "7.0", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7ce31739fe88a558370135db95bbeec1e7ddfc29" }, { "url": "https://git.kernel.org/stable/c/4c6d43db2a4d2cef3921e885cf34798f790d34ea" } ], "title": "net: dst_metadata: fix false-positive memcpy overflow in tun_dst_unclone", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-80615", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:18:51.546693Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:30.819Z" } } ] } }