CVE-2026-72407

In the Linux kernel, the following vulnerability has been resolved:

geneve: validate inner network offset in geneve_gro_complete()

Even with both paths gated on gs->gro_hint, geneve_gro_complete()

re-derives the inner dispatch type and length from the packet and the

current gs->gro_hint, independently of geneve_gro_receive(). The two can

disagree if gs->gro_hint flips under a concurrent geneve_quiesce()/

geneve_unquiesce() (sk_user_data is NULL across a synchronize_net()), or if

the re-read option bytes differ from the ones receive parsed.

geneve_gro_receive() already records the inner network header position in

NAPI_GRO_CB()->inner_network_offset. Have geneve_gro_complete() compute the

offset it is about to dispatch at, adding ETH_HLEN in the ETH_P_TEB case

where eth_gro_complete() steps over the inner MAC header, and bail out if

it lands past inner_network_offset.

Use a lower bound rather than exact equality: between gh_len and the inner

L3 header, geneve_gro_receive() may also have pulled an inner VLAN tag

(vlan_gro_receive() advances the recorded offset past it), which only moves

inner_network_offset further out. A valid frame therefore always satisfies

inner_nh <= inner_network_offset, while a gh_len inflated by a hint

gro_receive() did not honour dispatches past the validated inner header,

i.e. the out-of-bounds completion. Only the latter is rejected.