CVE-2024-35910 — tcp: properly terminate timers for kernel sockets
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+2
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 10.0 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux |
≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < 93f0133b9d589cc6e865f254ad9be3e9d8133f50version 4.2≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < 151c9c724d05d5b0dd8acd3e11cb69ef1f2dbada≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < 899265c1389fe022802aae73dbf13ee08837a35a≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < c1ae4d1e76eacddaacb958b67cd942082f800c87≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < 91b243de910a9ac8476d40238ab3dbfeedd5b7de≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < 2e43d8eba6edd1cf05a3a20fdd77688fa7ec16a4≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < e3e27d2b446deb1f643758a0c4731f5c22492810 and 1 more≥ 26abe14379f8e2fa3fd1bcf97c9a7ad9364886fe and < 44e62f5d35678686734afd47c6a421ad30772e7f |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | version 6.9-rc1≥ 6.7 and < 6.8.5≥ 6.2 and < 6.6.26≥ 5.16 and < 6.1.85≥ 5.11 and < 5.15.154≥ 5.5 and < 5.10.215≥ 4.20 and < 5.4.274≥ 4.2 and < 4.19.312 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
| 5.8 | CVSS 3.1 | Medium | 1.0 | 4.7 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.8 | CVSS 3.1 | Medium | 1.0 | 4.7 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 5.8 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
| 5.8 | CVSS 3.1 | Medium | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H (score shown at the top: nvd@nist.gov) Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel, debian/debian linux
- CVSS changed · 5.8
- Source status changed · → Modified
- Record created in this database
- 2024
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
14 on the record
- git.kernel.org/stable/c/151c9c724d05d5b0dd8acd3e11cb69ef1f2dbada
- git.kernel.org/stable/c/899265c1389fe022802aae73dbf13ee08837a35a
- git.kernel.org/stable/c/91b243de910a9ac8476d40238ab3dbfeedd5b7de
- git.kernel.org/stable/c/93f0133b9d589cc6e865f254ad9be3e9d8133f50
- git.kernel.org/stable/c/e3e27d2b446deb1f643758a0c4731f5c22492810
- git.kernel.org/stable/c/44e62f5d35678686734afd47c6a421ad30772e7f
- git.kernel.org/stable/c/2e43d8eba6edd1cf05a3a20fdd77688fa7ec16a4
- git.kernel.org/stable/c/c1ae4d1e76eacddaacb958b67cd942082f800c87
- lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- github.com/advisories/GHSA-f8qw-j52x-qgrm
- nvd.nist.gov/vuln/detail/CVE-2024-35910
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- lists.debian.org/debian-lts-announce/2024/06/msg00020.html
- cert-portal.siemens.com/productcert/html/ssa-265688.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 8h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 8h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2024-35910 is "tcp: properly terminate timers for kernel sockets", rated Medium. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.8 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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