---
id: CVE-2026-22979
title: 'net: fix memory leak in skb_segment_list for GRO packets'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: fix memory leak in skb_segment_list for GRO packets

  When skb_segment_list() is called during packet forwarding, it handles
  packets that were aggregated by the GRO…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 2eeab8c47c3c0276e0746bc382f405c9a236a5ad <
    0b27828ebd1ed3107d7929c3737adbe862e99e74
  - >-
    Linux >= fc126c1d51e9552eacd2d717b9ffe9262a8a4cd6 <
    88bea149db2057112af3aaf63534b24fab5858ab
  - >-
    Linux >= ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 <
    3264881431e308b9c72cb8a0159d57a56d67dd79
  - >-
    Linux >= ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 <
    c114a32a2e70b82d447f409f7ffcfa3058f9d5bd
  - >-
    Linux >= ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 <
    238e03d0466239410b72294b79494e43d4fabe77
  - Linux d225b0ac96dc40d7e8ae2bc227eb2c56e130975f
  - Linux 5b3b67f731296027cceb3efad881ae281213f86f
  - Linux >= 6.1.85 < 6.1.161
  - Linux >= 6.6.26 < 6.6.121
  - Linux >= 5.15.154 < 5.16
  - Linux >= 6.8.5 < 6.9
  - Linux 6.9
published: '2026-01-23'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:44:26.536Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-22979'
references:
  - url: 'https://git.kernel.org/stable/c/0b27828ebd1ed3107d7929c3737adbe862e99e74'
  - url: 'https://git.kernel.org/stable/c/88bea149db2057112af3aaf63534b24fab5858ab'
  - url: 'https://git.kernel.org/stable/c/3264881431e308b9c72cb8a0159d57a56d67dd79'
  - url: 'https://git.kernel.org/stable/c/c114a32a2e70b82d447f409f7ffcfa3058f9d5bd'
  - url: 'https://git.kernel.org/stable/c/238e03d0466239410b72294b79494e43d4fabe77'
tags:
  - cve.org
epss: 0.00139
epssPercentile: 0.03626
ingestedAt: '2026-09-08T15:33:26.994Z'
---

## Overview

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

net: fix memory leak in skb_segment_list for GRO packets

When skb_segment_list() is called during packet forwarding, it handles
packets that were aggregated by the GRO engine.

Historically, the segmentation logic in skb_segment_list assumes that
individual segments are split from a parent SKB and may need to carry
their own socket memory accounting. Accordingly, the code transfers
truesize from the parent to the newly created segments.

Prior to commit ed4cccef64c1 ("gro: fix ownership transfer"), this
truesize subtraction in skb_segment_list() was valid because fragments
still carry a reference to the original socket.

However, commit ed4cccef64c1 ("gro: fix ownership transfer") changed
this behavior by ensuring that fraglist entries are explicitly
orphaned (skb->sk = NULL) to prevent illegal orphaning later in the
stack. This change meant that the entire socket memory charge remained
with the head SKB, but the corresponding accounting logic in
skb_segment_list() was never updated.

As a result, the current code unconditionally adds each fragment's
truesize to delta_truesize and subtracts it from the parent SKB. Since
the fragments are no longer charged to the socket, this subtraction
results in an effective under-count of memory when the head is freed.
This causes sk_wmem_alloc to remain non-zero, preventing socket
destruction and leading to a persistent memory leak.

The leak can be observed via KMEMLEAK when tearing down the networking
environment:

unreferenced object 0xffff8881e6eb9100 (size 2048):
  comm "ping", pid 6720, jiffies 4295492526
  backtrace:
    kmem_cache_alloc_noprof+0x5c6/0x800
    sk_prot_alloc+0x5b/0x220
    sk_alloc+0x35/0xa00
    inet6_create.part.0+0x303/0x10d0
    __sock_create+0x248/0x640
    __sys_socket+0x11b/0x1d0

Since skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST
packets constructed by GRO, the truesize adjustment is removed.

The call to skb_release_head_state() must be preserved. As documented in
commit cf673ed0e057 ("net: fix fraglist segmentation reference count
leak"), it is still required to correctly drop references to SKB
extensions that may be overwritten during __copy_skb_header().

## Affected

- `Linux >= 2eeab8c47c3c0276e0746bc382f405c9a236a5ad < 0b27828ebd1ed3107d7929c3737adbe862e99e74`
- `Linux >= fc126c1d51e9552eacd2d717b9ffe9262a8a4cd6 < 88bea149db2057112af3aaf63534b24fab5858ab`
- `Linux >= ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 < 3264881431e308b9c72cb8a0159d57a56d67dd79`
- `Linux >= ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 < c114a32a2e70b82d447f409f7ffcfa3058f9d5bd`
- `Linux >= ed4cccef64c1d0d5b91e69f7a8a6697c3a865486 < 238e03d0466239410b72294b79494e43d4fabe77`
- `Linux d225b0ac96dc40d7e8ae2bc227eb2c56e130975f`
- `Linux 5b3b67f731296027cceb3efad881ae281213f86f`
- `Linux >= 6.1.85 < 6.1.161`
- `Linux >= 6.6.26 < 6.6.121`
- `Linux >= 5.15.154 < 5.16`
- `Linux >= 6.8.5 < 6.9`
- `Linux 6.9`

## Remediation

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