---
id: CVE-2026-68290
title: 'rds: tcp: unregister sysctl before tearing down listen socket'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  rds: tcp: unregister sysctl before tearing down listen socket

  rds_tcp_exit_net() frees the per-netns RDS TCP listen socket via
  rds_tcp_kill_sock() before unregistering…
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 >= de8d6de0ee27be4b2b1e5b06f04aeacbabbba492 <
    80fffed08dc1c10e971066941d2daa56253f1552
  - >-
    Linux >= 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c <
    16df2d154ec82e2f7e7585b4fa154751ba37729a
  - >-
    Linux >= 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c <
    3aa13fe0c1bb7bc5312f878e61523e5d8cf3f85d
  - >-
    Linux >= 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c <
    167e54c703ccd4fa028feb568b0d1002020cff86
  - Linux >= 6.12.10 < 6.12.101
  - Linux 6.13
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:46:38.665842Z'
published: '2026-08-10'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:53:06.461Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68290'
references:
  - url: 'https://git.kernel.org/stable/c/80fffed08dc1c10e971066941d2daa56253f1552'
  - url: 'https://git.kernel.org/stable/c/16df2d154ec82e2f7e7585b4fa154751ba37729a'
  - url: 'https://git.kernel.org/stable/c/3aa13fe0c1bb7bc5312f878e61523e5d8cf3f85d'
  - url: 'https://git.kernel.org/stable/c/167e54c703ccd4fa028feb568b0d1002020cff86'
tags:
  - cve.org
epss: 0.00125
epssPercentile: 0.01985
ingestedAt: '2026-10-16T17:24:46.855Z'
---

## Overview

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

rds: tcp: unregister sysctl before tearing down listen socket

rds_tcp_exit_net() frees the per-netns RDS TCP listen socket via
rds_tcp_kill_sock() before unregistering the per-netns sysctl table.  Since
rds_tcp_skbuf_handler() derives the netns from
rtn->rds_tcp_listen_sock->sk, a concurrent sysctl write can race with
netns teardown and dereference the freed socket/sk.

KASAN reports the race as:

  BUG: KASAN: slab-use-after-free in rds_tcp_skbuf_handler+0x2aa/0x2e0
  rds_tcp_skbuf_handler              net/rds/tcp.c:721
  proc_sys_call_handler              fs/proc/proc_sysctl.c
  vfs_write                          fs/read_write.c
  __x64_sys_pwrite64                 fs/read_write.c

Fix this by unregistering the RDS TCP sysctl table before calling
rds_tcp_kill_sock().  unregister_net_sysctl_table() prevents new sysctl
handlers from starting and waits for in-flight handlers to finish, so
the listen socket can then be released safely. The fix was tested
against the linked reproducer.

## Affected

- `Linux >= de8d6de0ee27be4b2b1e5b06f04aeacbabbba492 < 80fffed08dc1c10e971066941d2daa56253f1552`
- `Linux >= 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c < 16df2d154ec82e2f7e7585b4fa154751ba37729a`
- `Linux >= 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c < 3aa13fe0c1bb7bc5312f878e61523e5d8cf3f85d`
- `Linux >= 7f5611cbc4871c7fb1ad36c2e5a9edad63dca95c < 167e54c703ccd4fa028feb568b0d1002020cff86`
- `Linux >= 6.12.10 < 6.12.101`
- `Linux 6.13`

## Remediation

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