---
id: CVE-2026-89565
title: 'ipip: fix skb leak in collect_md mode when metadata_dst allocation fails'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipip: fix skb leak in collect_md mode when metadata_dst allocation fails

  In collect_md mode ipip_tunnel_rcv() returns 0 without freeing the skb
  when ip_tun_rx_dst() fa…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-772
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 <
    1909df2d066424767429e13053eb9701263430ef
  - >-
    Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 <
    c4dc23de4cc75e4e304170b31bb8aeeacd5cb990
  - >-
    Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 <
    6d8c5b266d0035a061573843a7243be068eb6118
  - >-
    Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 <
    31e4be21dacee49395013caae28576484a049a4f
  - >-
    Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 <
    fd01f1a3ed4a189a784654f7c69eb565872f2e12
  - >-
    Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 <
    6776efe4a52f289a3fc18f8adf19b035a7d8e1bb
  - Linux 4.9
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:48:58.760Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89565'
references:
  - url: 'https://git.kernel.org/stable/c/1909df2d066424767429e13053eb9701263430ef'
  - url: 'https://git.kernel.org/stable/c/c4dc23de4cc75e4e304170b31bb8aeeacd5cb990'
  - url: 'https://git.kernel.org/stable/c/6d8c5b266d0035a061573843a7243be068eb6118'
  - url: 'https://git.kernel.org/stable/c/31e4be21dacee49395013caae28576484a049a4f'
  - url: 'https://git.kernel.org/stable/c/fd01f1a3ed4a189a784654f7c69eb565872f2e12'
  - url: 'https://git.kernel.org/stable/c/6776efe4a52f289a3fc18f8adf19b035a7d8e1bb'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89565.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89565'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532185'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89565'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89565'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89565.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00173
epssPercentile: 0.06625
ingestedAt: '2026-09-14T15:23:07.451Z'
---

## Overview

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

ipip: fix skb leak in collect_md mode when metadata_dst allocation fails

In collect_md mode ipip_tunnel_rcv() returns 0 without freeing the skb
when ip_tun_rx_dst() fails to allocate the metadata_dst. ipip_rcv() and
mplsip_rcv() are registered as xfrm_tunnel handlers, so tunnel4_rcv()
and tunnelmpls4_rcv() read the zero return as "the packet has been
consumed" and do not free it either. The skb is leaked.

The other tunnel drivers all dispose of the packet at this point:
ip6_tunnel.c jumps to its drop label, ip_gre.c and ip6_gre.c return
PACKET_REJECT, which makes gre_rcv() free the skb. Only ipip returns 0.

Jump to the existing drop label instead. It frees the skb and still
returns 0, so the packet keeps being reported as consumed, which is what
we want here: the outer header has already been pulled, and neither the
remaining handlers nor an ICMP unreachable have any use for it.

Triggering this needs an ipip or mplsip tunnel in collect_md mode and an
atomic allocation failure, which is why it has gone unnoticed.

## Affected

- `Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 < 1909df2d066424767429e13053eb9701263430ef`
- `Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 < c4dc23de4cc75e4e304170b31bb8aeeacd5cb990`
- `Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 < 6d8c5b266d0035a061573843a7243be068eb6118`
- `Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 < 31e4be21dacee49395013caae28576484a049a4f`
- `Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 < fd01f1a3ed4a189a784654f7c69eb565872f2e12`
- `Linux >= cfc7381b3002756b1dcada32979e942aa3126e31 < 6776efe4a52f289a3fc18f8adf19b035a7d8e1bb`
- `Linux 4.9`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89565.json)