CVE-2024-35910tcp: properly terminate timers for kernel sockets

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: properly terminate timers for kernel sockets We had various syzbot reports about tcp timers firing after the corresponding netns has been dismantled. Fortunately Josef Bacik could trigger the issue more often, and could test a patch I wrote two years ago. When TCP sockets are closed, we call inet_csk_clear_xmit_timers() to 'stop' the timers. inet_csk_clear_xmit_timers() can be called from any context, including when socket lock is held. This is the reason it uses sk_stop_timer(), aka del_timer(). This means that ongoing timers might finish much later. For user sockets, this is fine because each running timer holds a reference on the socket, and the user socket holds a reference on the netns. For kernel sockets, we risk that the netns is freed before timer can complete, because kernel sockets do not hold reference on the netns. This patch adds inet_csk_clear_xmit_timers_sync() function that using sk_stop_timer_sync() to make sure all timers are terminated before the kernel socket is released. Modules using kernel sockets close them in their netns exit() handler. Also add sock_not_owned_by_me() helper to get LOCKDEP support : inet_csk_clear_xmit_timers_sync() must not be called while socket lock is held. It is very possible we can revert in the future commit 3a58f13a881e ("net: rds: acquire refcount on TCP sockets") which attempted to solve the issue in rds only. (net/smc/af_smc.c and net/mptcp/subflow.c have similar code) We probably can remove the check_net() tests from tcp_out_of_resources() and __tcp_close() in the future.

Timeline

Scores

EPSS (exploitation in 30 days)

0.26% · top 82% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < 93f0133b9d589cc6e865f254ad9be3e9d8133f50
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < 44e62f5d35678686734afd47c6a421ad30772e7f
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < e3e27d2b446deb1f643758a0c4731f5c22492810
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < 2e43d8eba6edd1cf05a3a20fdd77688fa7ec16a4
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < 91b243de910a9ac8476d40238ab3dbfeedd5b7de
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < c1ae4d1e76eacddaacb958b67cd942082f800c87
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < 899265c1389fe022802aae73dbf13ee08837a35a
  • affected 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe – < 151c9c724d05d5b0dd8acd3e11cb69ef1f2dbada

• Linux · Linux

  • affected 4.2
  • unaffected < 4.2
  • unaffected 4.19.312 – ≤ 4.19.*
  • unaffected 5.4.274 – ≤ 5.4.*
  • unaffected 5.10.215 – ≤ 5.10.*
  • unaffected 5.15.154 – ≤ 5.15.*
  • unaffected 6.1.85 – ≤ 6.1.*
  • unaffected 6.6.26 – ≤ 6.6.*
  • unaffected 6.8.5 – ≤ 6.8.*
  • unaffected 6.9 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2024-35628 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2024-35910](https://cveledger.app/badge/CVE-2024-35910.svg)](https://cveledger.app/cve/CVE-2024-35910)

Record last updated 15 Oct 2026, 00:41 UTC.