---
id: CVE-2026-68143
title: 'net: slip: serialize receive against buffer reallocation'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: slip: serialize receive against buffer reallocation

  sl_realloc_bufs() replaces rbuff and updates buffsize while holding
  sl->lock. slip_receive_buf() reads those f…
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'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    8180daf2b66155f84ec4f9e3f95488c8a3421716
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    189a550eb7e1dc10018718ddfc46d003ffe58653
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    1be09d175b627fad7f6bec7ad27b8a4a99863912
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    eb3836eab47487823f362e6985e170a1e15f20fd
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    44401f7dd9940ced7098930ef64f5a332f279fc2
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    5d07b178bef511d69558cfc89fe1129258dc39f8
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    0e37bbd6d617eb52bace49390e99eaedc1af73ce
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    ee7f9bb9320add61f7b367d7e6cd55e3a3a4d65d
  - Linux 2.6.12
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:44:44.088088Z'
published: '2026-08-10'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:52:59.779Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68143'
references:
  - url: 'https://git.kernel.org/stable/c/8180daf2b66155f84ec4f9e3f95488c8a3421716'
  - url: 'https://git.kernel.org/stable/c/189a550eb7e1dc10018718ddfc46d003ffe58653'
  - url: 'https://git.kernel.org/stable/c/1be09d175b627fad7f6bec7ad27b8a4a99863912'
  - url: 'https://git.kernel.org/stable/c/eb3836eab47487823f362e6985e170a1e15f20fd'
  - url: 'https://git.kernel.org/stable/c/44401f7dd9940ced7098930ef64f5a332f279fc2'
  - url: 'https://git.kernel.org/stable/c/5d07b178bef511d69558cfc89fe1129258dc39f8'
  - url: 'https://git.kernel.org/stable/c/0e37bbd6d617eb52bace49390e99eaedc1af73ce'
  - url: 'https://git.kernel.org/stable/c/ee7f9bb9320add61f7b367d7e6cd55e3a3a4d65d'
tags:
  - cve.org
epss: 0.00139
epssPercentile: 0.02893
ingestedAt: '2026-10-16T17:24:46.843Z'
---

## Overview

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

net: slip: serialize receive against buffer reallocation

sl_realloc_bufs() replaces rbuff and updates buffsize while holding
sl->lock. slip_receive_buf() reads those fields and writes through rbuff
without holding the lock.

An MTU change can therefore race with receive processing. An MTU shrink
can expose the new smaller rbuff with the old larger bound, causing an
out-of-bounds write. A receive callback which already loaded the old
rbuff can instead continue writing after that buffer has been freed.

Serialize receive processing with sl_realloc_bufs() by holding sl->lock
while consuming each receive batch.

## Affected

- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 8180daf2b66155f84ec4f9e3f95488c8a3421716`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 189a550eb7e1dc10018718ddfc46d003ffe58653`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 1be09d175b627fad7f6bec7ad27b8a4a99863912`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < eb3836eab47487823f362e6985e170a1e15f20fd`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 44401f7dd9940ced7098930ef64f5a332f279fc2`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 5d07b178bef511d69558cfc89fe1129258dc39f8`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 0e37bbd6d617eb52bace49390e99eaedc1af73ce`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ee7f9bb9320add61f7b367d7e6cd55e3a3a4d65d`
- `Linux 2.6.12`

## Remediation

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