---
id: CVE-2026-80841
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/packet: defer vmalloc TX_RING free until skbs finish

  AF_PACKET TX_RING skbs keep a raw pointer to their ring frame
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/packet: defer vmalloc TX_RING free until skbs finish

  AF_PACKET TX_RING skbs keep a raw pointer to their ring frame. The skb
  page references preserve page-backed ri…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b013840810c221f2b0cf641d01531526052dc1fb <
    4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c
  - >-
    Linux >= b013840810c221f2b0cf641d01531526052dc1fb <
    ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b
  - >-
    Linux >= b013840810c221f2b0cf641d01531526052dc1fb <
    0189dce07db2dc059ae0570e06758ec4233c6e11
  - >-
    Linux >= b013840810c221f2b0cf641d01531526052dc1fb <
    550d00aa58193fb649a09a9c9e338c685adad784
  - >-
    Linux >= b013840810c221f2b0cf641d01531526052dc1fb <
    992cc9f94ca924089a506ba9b327caa9af797529
  - Linux 3.14
published: '2026-09-04'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:20.800'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80841'
references:
  - url: 'https://git.kernel.org/stable/c/0189dce07db2dc059ae0570e06758ec4233c6e11'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00168
epssPercentile: 0.06489
ingestedAt: '2026-09-11T16:45:47.925Z'
---

## Overview

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

net/packet: defer vmalloc TX_RING free until skbs finish

AF_PACKET TX_RING skbs keep a raw pointer to their ring frame. The skb
page references preserve page-backed ring blocks after pg_vec is freed,
but they do not preserve a vmalloc mapping.

tpacket_destruct_skb() currently drops the pending reference before
writing the timestamp and TP_STATUS_AVAILABLE to the frame. Move the
decrement after those stores. The smp_wmb() in __packet_set_status()
orders the frame stores before the decrement.

Also recheck pending TX frames under pg_vec_lock before non-closing
ring replacement, so a racing send cannot add a pending skb between
the initial check and the ring swap.

Ring allocation can produce a mixture of page-backed and vmalloc-backed
blocks. Allocate deferred-work storage during TX ring setup when the
first vmalloc-backed block is encountered, and keep its pointer in the
pg_vec allocation header. If allocation fails, return -ENOMEM from ring
setup. On socket close, a non-NULL pointer identifies a vmalloc-backed
vector without a scan. If TX skbs remain, defer the whole vector to
system_long_wq.

After pg_vec is detached, a late destructor can skip the pending
decrement. Use socket write-memory accounting as the deferred lifetime
gate instead: an skb remains charged through its final sock_wfree(),
after all ring-frame accesses. The delayed work retains a socket
reference and reschedules itself until no TX skbs remain.

Move pending_refcnt release to packet_sock_destruct() so late skb
destructors and deferred cleanup can safely use it after
packet_release(). Page-backed teardown remains synchronous, and no lock
is added to the TX completion hot path.

## Remediation

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