{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72407", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.926Z", "datePublished": "2026-08-15T05:56:30.847Z", "dateUpdated": "2026-08-17T05:43:47.398Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:43:47.398Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngeneve: validate inner network offset in geneve_gro_complete()\n\nEven with both paths gated on gs->gro_hint, geneve_gro_complete()\nre-derives the inner dispatch type and length from the packet and the\ncurrent gs->gro_hint, independently of geneve_gro_receive(). The two can\ndisagree if gs->gro_hint flips under a concurrent geneve_quiesce()/\ngeneve_unquiesce() (sk_user_data is NULL across a synchronize_net()), or if\nthe re-read option bytes differ from the ones receive parsed.\n\ngeneve_gro_receive() already records the inner network header position in\nNAPI_GRO_CB()->inner_network_offset. Have geneve_gro_complete() compute the\noffset it is about to dispatch at, adding ETH_HLEN in the ETH_P_TEB case\nwhere eth_gro_complete() steps over the inner MAC header, and bail out if\nit lands past inner_network_offset.\n\nUse a lower bound rather than exact equality: between gh_len and the inner\nL3 header, geneve_gro_receive() may also have pulled an inner VLAN tag\n(vlan_gro_receive() advances the recorded offset past it), which only moves\ninner_network_offset further out. A valid frame therefore always satisfies\ninner_nh <= inner_network_offset, while a gh_len inflated by a hint\ngro_receive() did not honour dispatches past the validated inner header,\ni.e. the out-of-bounds completion. Only the latter is rejected." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "baseScore": 10, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The bug is in geneve_gro_complete() on the NAPI GRO receive path for UDP-encapsulated GENEVE frames; a remote peer can deliver crafted packets to a listening GENEVE UDP port on cloud/overlay hosts without local access.\nAC:L - An attacker can reliably trigger the mismatch by flooding GRO-eligible GENEVE frames with crafted GRO-hint options and timing them against geneve_quiesce()/geneve_unquiesce() during changelink, or self-trigger that race with CAP_NET_ADMIN in a user namespace.\nPR:N - Exploitation requires no credentials or capabilities on the victim; the attacker only needs network reachability to a host already running a gro_hint-enabled GENEVE tunnel, which is common on overlay networks.\nUI:N - Exploitation is fully automated through malicious network traffic and does not require any victim user action such as mounting filesystems or opening files.\nS:C - On cloud/overlay deployments a tenant VM or remote overlay peer can corrupt the hypervisor/host kernel through underlay GENEVE GRO processing, crossing the guest/host security boundary.\nC:H - When gro_complete() dispatches past inner_network_offset, eth_gro_complete() and inet_gro_complete() read headers from attacker-influenced out-of-bounds skb memory, enabling arbitrary kernel memory disclosure.\nI:H - The same out-of-bounds gro_complete dispatch writes header fields (e.g., iph->tot_len and iph->check in inet_gro_complete()), causing memory corruption that can be leveraged for arbitrary write or code execution.\nA:H - Out-of-bounds GRO completion can cause kernel oops/panic or forced skb drop under error paths, enabling repeatable remote denial of service against the host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/geneve.c" ], "versions": [ { "version": "fd0dd796576e1a560e1441e665810129f0a82be0", "lessThan": "e2087447f562692ff0cd08a0554d8d4ad083aa5c", "status": "affected", "versionType": "git" }, { "version": "fd0dd796576e1a560e1441e665810129f0a82be0", "lessThan": "cbb0d30a1ad6fc9439b1dc9b4f5a7a9140d3b11f", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/geneve.c" ], "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/e2087447f562692ff0cd08a0554d8d4ad083aa5c" }, { "url": "https://git.kernel.org/stable/c/cbb0d30a1ad6fc9439b1dc9b4f5a7a9140d3b11f" } ], "title": "geneve: validate inner network offset in geneve_gro_complete()", "x_generator": { "engine": "bippy-1.2.0" } } } }