In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: support IPIP tunnel with direct xmit
The combination of IPIP tunnel with direct xmit, eg. bridge device, breaks because no dst_entry is provided to check the skb headroom and to set the iph->frag_off field. This leads to invalid dst usage and can trigger a crash in the tunnel transmit path.
Fix this by moving dst_cache and dst_cookie out of the runtime union so that they can be shared by neighbour, xfrm, and direct tunnel flows. For FLOW_OFFLOAD_XMIT_DIRECT tuples carrying tunnel metadata, preserve route state in these shared fields and release it through the common dst release path.
Since dst_entry is now available to the three supported xmit modes and dst_release() already deals with NULL dst, remove the xmit type check in nft_flow_dst_release(). Moreover, skip the check if the dst entry is NULL in nf_flow_dst_check() which is now the case for the direct xmit case.
Based on patch from Rein Wei <[email protected]>.
CVSS Details
- CVSS 3.1 Base Score: 9.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Ubuntu | — | Upgrade linux-image-realtime-64k-hwe-26.04Upgrade linux-image-azure-fde-lts-26.04Upgrade linux-image-oracle-64k-7.0Upgrade linux-image-ibmUpgrade linux-image-realtime-64k-7.0Upgrade linux-image-virtualUpgrade linux-image-virtual-7.0Upgrade linux-image-7.0.0-1007-gkeUpgrade linux-image-gke-hwe-26.04Upgrade linux-image-oracle-64kUpgrade linux-image-gkeUpgrade linux-image-raspi-realtimeUpgrade linux-image-oracle-7.0Upgrade linux-image-virtual-hwe-24.04Upgrade linux-image-generic-hwe-26.04Upgrade linux-image-7.0.0-1007-gke-64kUpgrade linux-image-7.0.0-1017-azureUpgrade linux-image-generic-64k-7.0Upgrade linux-image-azure-7.0Upgrade linux-image-oem-7.0Upgrade linux-image-generic-64kUpgrade linux-image-generic-7.0Upgrade linux-image-generic-hwe-24.04Upgrade linux-image-7.0.0-1012-oracle-64kUpgrade linux-image-7.0.0-34-realtimeUpgrade linux-image-realtime-hwe-26.04Upgrade linux-image-gke-64k-hwe-26.04Upgrade linux-image-gcpUpgrade linux-image-aws-64kUpgrade linux-image-oracleUpgrade linux-image-virtual-hwe-26.04Upgrade linux-image-7.0.0-34-genericUpgrade linux-image-7.0.0-1013-aws-64kUpgrade linux-image-7.0.0-34-realtime-64kUpgrade linux-image-7.0.0-1014-oemUpgrade linux-image-7.0.0-34-generic-64kUpgrade linux-image-7.0.0-1016-azure-fdeUpgrade linux-image-gcp-64k-7.0Upgrade linux-image-realtime-7.0Upgrade linux-image-gke-64kUpgrade linux-image-azure-fde-7.0Upgrade linux-image-oem-26.04Upgrade linux-image-7.0.0-1012-oracleUpgrade linux-image-realtime-64kUpgrade linux-image-7.0.0-1013-awsUpgrade linux-image-raspiUpgrade linux-image-aws-7.0Upgrade linux-image-generic-64k-hwe-26.04Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-azure-fdeUpgrade linux-image-awsUpgrade linux-image-gcp-7.0Upgrade linux-image-7.0.0-1020-raspi-realtimeUpgrade linux-image-7.0.0-1020-raspiUpgrade linux-image-gcp-64kUpgrade linux-image-ibm-7.0Upgrade linux-image-aws-64k-7.0Upgrade linux-image-oem-26.04aUpgrade linux-image-7.0.0-1013-gcp-64kUpgrade linux-image-7.0.0-1014-ibmUpgrade linux-image-raspi-realtime-7.0Upgrade linux-image-gke-64k-7.0Upgrade linux-image-7.0.0-1013-gcpUpgrade linux-image-realtimeUpgrade linux-image-raspi-7.0Upgrade linux-image-gke-7.0Upgrade linux-image-genericUpgrade linux-image-azure-lts-26.04Upgrade linux-image-azure | Sep 24, 2026 | Aug 15, 2026 |
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