KEVWire

Security intelligence, with context.

Response snapshot Nov 3, 2026, 22:26 UTC

Back to the wire
Permalink
VulnerabilityCVE-2024-26923

Linux kernel: af_unix: Fix garbage collector racing against connect()

In the Linux kernel, the following vulnerability has been resolved: af_unix: Fix garbage collector racing against connect() Garbage collector does not take into account the risk of embryo getting enqueued during the garbage collection.

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2024-26923 (opens a new tab)

What happened

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

af_unix: Fix garbage collector racing against connect()

Garbage collector does not take into account the risk of embryo getting enqueued during the garbage collection. If such embryo has a peer that carries SCM_RIGHTS, two consecutive passes of scan_children() may see a different set of children. Leading to an incorrectly elevated inflight count, and then a dangling pointer within the gc_inflight_list.

sockets are AF_UNIX/SOCK_STREAM S is an unconnected socket L is a listening in-flight socket bound to addr, not in fdtable V's fd will be passed via sendmsg(), gets inflight count bumped

Continue reading

connect(S, addr) sendmsg(S, [V]); close(V) __unix_gc() ---------------- ------------------------- -----------

NS = unix_create1() skb1 = sock_wmalloc(NS) L = unix_find_other(addr) unix_state_lock(L) unix_peer(S) = NS // V count=1 inflight=0

NS = unix_peer(S) skb2 = sock_alloc() skb_queue_tail(NS, skb2[V])

// V became in-flight // V count=2 inflight=1

close(V)

// V count=1 inflight=1 // GC candidate condition met

for u in gc_inflight_list: if (total_refs == inflight_refs) add u to gc_candidates

// gc_candidates={L, V}

for u in gc_candidates: scan_children(u, dec_inflight)

// embryo (skb1) was not // reachable from L yet, so V's // inflight remains unchanged __skb_queue_tail(L, skb1) unix_state_unlock(L) for u in gc_candidates: if (u.inflight) scan_children(u, inc_inflight_move_tail)

// V count=1 inflight=2 (!)

If there is a GC-candidate listening socket, lock/unlock its state. This makes GC wait until the end of any ongoing connect() to that socket. After flipping the lock, a possibly SCM-laden embryo is already enqueued. And if there is another embryo coming, it can not possibly carry SCM_RIGHTS. At this point, unix_inflight() can not happen because unix_gc_lock is already taken. Inflight graph remains unaffected.

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2024-26923 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 3). Linux kernel: af_unix: Fix garbage collector racing against connect() (CVE-2024-26923). https://kevwire.com/record/CVE-2024-26923

MLA

"Linux kernel: af_unix: Fix garbage collector racing against connect() (CVE-2024-26923)." KEVWire, 3 Nov. 2026, kevwire.com/record/CVE-2024-26923.

Chicago

KEVWire. "Linux kernel: af_unix: Fix garbage collector racing against connect() (CVE-2024-26923)." Last modified November 3, 2026. https://kevwire.com/record/CVE-2024-26923.

Evidence summary (plain text)

Linux kernel: af_unix: Fix garbage collector racing against connect() (Apr 25, 2024).
In the Linux kernel, the following vulnerability has been resolved:

af_unix: Fix garbage collector racing against connect()

Garbage collector does not take into account the risk of embryo getting
enqueued during the garbage collection. If such embryo has a peer that
carries SCM_RIGHTS, two consecutive passes of scan_children() may see a
different set of children. Leading to an incorrectly elevated inflight
count, and then a dangling pointer within the gc_inflight_list.
CVSS 7.8 (version 3.1; evidence as of Nov 3, 2026; https://nvd.nist.gov/vuln/detail/CVE-2024-26923).
Sources:
NVD CVE-2024-26923: https://nvd.nist.gov/vuln/detail/CVE-2024-26923
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-03T20:56:06.501Z&lastModEndDate=2026-11-03T22:25:56.572Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2024-26923.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 3, 2026, 22:25 UTC. Ingestion is not an independent editorial investigation.

NVD status: Modified. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

Your account

Email alerts

Email alerts are coming as part of KEVWire Premium: join the waitlist. To follow your stack today, use its RSS feed, which honors your filters, or connect an AI agent through the API.

Suggest an improvement

Ideas, missing sources, corrections, and bugs are all welcome. No account needed. Suggestions are reviewed by a person before anything changes.

Record details

Record detail