{"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"}}}}