CVE-2024-26923

Aliases:UBUNTU-CVE-2024-26923DEBIAN-CVE-2024-26923
Advisory lineage Upstream: 0 Downstream: 248
Modified
Published: 24 Apr 2024, 21:49
Last modified:05 Aug 2026, 11:28

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.21% LOW
0% probability +0.20%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

24 Apr 2024, 21:49
Published
Vulnerability first disclosed
05 Aug 2026, 11:28
Last Modified
Vulnerability information updated

Description

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 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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.21%• Percentile: 11%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Systems

  • debian•linux

    < 5.10.216-1 | < 6.1.90-1 | < 6.8.9-1 | < 6.8.9-1

  • ubuntu•linux

    all | < 4.4.0-257.291 | < 4.15.0-227.239 | < 5.4.0-189.209 | < 5.15.0-116.126 | < 6.8.0-38.38

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    < 4.4.0-1134.140 | < 4.4.0-1172.187 | < 4.15.0-1170.183 | < 5.4.0-1128.138 | < 5.15.0-1065.71 | < 6.8.0-1011.12

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1065.71~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1128.138~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    < 6.5.0-1023.23~22.04.1

  • ubuntu•linux-aws-6.8

    < 6.8.0-1011.12~22.04.1

  • ubuntu•linux-aws-fips

    < 4.15.0-2109.115 | all | < 5.4.0-1128.138+fips1 | < 5.15.0-1065.71+fips1

  • ubuntu•linux-aws-hwe

    < 4.15.0-1170.183~16.04.1

  • ubuntu•linux-azure

    < 4.15.0-1179.194~14.04.1 | < 4.15.0-1179.194~16.04.1 | all | < 5.4.0-1133.140 | < 5.15.0-1068.77 | < 6.8.0-1010.10

  • ubuntu•linux-azure-4.15

    < 4.15.0-1179.194

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1068.77~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1133.140~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    < 6.5.0-1024.25~22.04.1

  • ubuntu•linux-azure-6.8

    < 6.8.0-1010.10~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | < 5.15.0-1068.77.1

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fips

    < 4.15.0-2088.94 | all | < 5.4.0-1133.140+fips1 | < 5.15.0-1068.77+fips1

  • ubuntu•linux-bluefield

    all | < 5.4.0-1088.95 | < 5.15.0-1047.49

  • ubuntu•linux-fips

    < 4.4.0-1103.110 | all | < 4.15.0-1125.136 | < 5.4.0-1102.112 | < 5.15.0-115.125+fips1

  • ubuntu•linux-gcp

    < 4.15.0-1164.181~16.04.1 | all | < 5.4.0-1132.141 | < 5.15.0-1064.72 | < 6.8.0-1010.11

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1164.181

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.15

    < 5.15.0-1065.73~20.04.1

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1132.141~18.04.1

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.2

    all

  • ubuntu•linux-gcp-6.5

    < 6.5.0-1024.26~22.04.1

  • ubuntu•linux-gcp-fips

    < 4.15.0-2072.77 | all | < 5.4.0-1132.141+fips1 | < 5.15.0-1064.72+fips1

  • ubuntu•linux-gke

    all | < 5.15.0-1062.68 | < 6.8.0-1006.9

  • ubuntu•linux-gke-4.15

    all

Showing first 50 affected entries in server-rendered view.

References (43)