---
id: CVE-2024-26640
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tcp: add sanity checks to rx zerocopy

  TCP rx zerocopy intent is to map pages initially allocated
  from NIC drivers, not pages owned by a fs.

  This patch adds to can_map…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tcp: add sanity checks to rx zerocopy

  TCP rx zerocopy intent is to map pages initially allocated
  from NIC drivers, not pages owned by a fs.

  This patch adds to can_map…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 4.18, < 5.10.210'
  - 'linux_kernel >= 5.11, < 5.15.149'
  - 'linux_kernel >= 5.16, < 6.1.77'
  - 'linux_kernel >= 6.2, < 6.6.16'
  - 'linux_kernel >= 6.7, < 6.7.4'
  - linux_kernel = 6.8
  - debian_linux = 10.0
patched:
  - linux_kernel 6.7.4
published: '2024-03-18'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-26640'
references:
  - url: 'https://git.kernel.org/stable/c/1b8adcc0e2c584fec778add7777fe28e20781e60'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/577e4432f3ac810049cb7e6b71f4d96ec7c6e894'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/718f446e60316bf606946f7f42367d691d21541e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b383d4ea272fe5795877506dcce5aad1f6330e5e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d15cc0f66884ef2bed28c7ccbb11c102aa3a0760'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f48bf9a83b1666d934247cb58a9887d7b3127b6f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1b8adcc0e2c584fec778add7777fe28e20781e60'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/577e4432f3ac810049cb7e6b71f4d96ec7c6e894'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/718f446e60316bf606946f7f42367d691d21541e'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/b383d4ea272fe5795877506dcce5aad1f6330e5e'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/d15cc0f66884ef2bed28c7ccbb11c102aa3a0760'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/f48bf9a83b1666d934247cb58a9887d7b3127b6f'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.0024
epssPercentile: 0.13379
ingestedAt: '2026-08-05T10:46:47.437Z'
---

## Overview

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

tcp: add sanity checks to rx zerocopy

TCP rx zerocopy intent is to map pages initially allocated
from NIC drivers, not pages owned by a fs.

This patch adds to can_map_frag() these additional checks:

- Page must not be a compound one.
- page->mapping must be NULL.

This fixes the panic reported by ZhangPeng.

syzbot was able to loopback packets built with sendfile(),
mapping pages owned by an ext4 file to TCP rx zerocopy.

r3 = socket$inet_tcp(0x2, 0x1, 0x0)
mmap(&(0x7f0000ff9000/0x4000)=nil, 0x4000, 0x0, 0x12, r3, 0x0)
r4 = socket$inet_tcp(0x2, 0x1, 0x0)
bind$inet(r4, &(0x7f0000000000)={0x2, 0x4e24, @multicast1}, 0x10)
connect$inet(r4, &(0x7f00000006c0)={0x2, 0x4e24, @empty}, 0x10)
r5 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\x00',
    0x181e42, 0x0)
fallocate(r5, 0x0, 0x0, 0x85b8)
sendfile(r4, r5, 0x0, 0x8ba0)
getsockopt$inet_tcp_TCP_ZEROCOPY_RECEIVE(r4, 0x6, 0x23,
    &(0x7f00000001c0)={&(0x7f0000ffb000/0x3000)=nil, 0x3000, 0x0, 0x0, 0x0,
    0x0, 0x0, 0x0, 0x0}, &(0x7f0000000440)=0x40)
r6 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\x00',
    0x181e42, 0x0)

## Affected

- `linux_kernel >= 4.18, < 5.10.210`
- `linux_kernel >= 5.11, < 5.15.149`
- `linux_kernel >= 5.16, < 6.1.77`
- `linux_kernel >= 6.2, < 6.6.16`
- `linux_kernel >= 6.7, < 6.7.4`
- `linux_kernel = 6.8`
- `debian_linux = 10.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.7.4`