CVE-2024-56640

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2024-12-27. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

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

net/smc: fix LGR and link use-after-free issue

We encountered a LGR/link use-after-free issue, which manifested as the LGR/link refcnt reaching 0 early and entering the clear process, making resource access unsafe.

refcount_t: addition on 0; use-after-free. WARNING: CPU: 14 PID: 107447 at lib/refcount.c:25 refcount_warn_saturate+0x9c/0x140 Workqueue: events smc_lgr_terminate_work [smc] Call trace: refcount_warn_saturate+0x9c/0x140 __smc_lgr_terminate.part.45+0x2a8/0x370 [smc] smc_lgr_terminate_work+0x28/0x30 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118

or

refcount_t: underflow; use-after-free. WARNING: CPU: 6 PID: 93140 at lib/refcount.c:28 refcount_warn_saturate+0xf0/0x140 Workqueue: smc_hs_wq smc_listen_work [smc] Call trace: refcount_warn_saturate+0xf0/0x140 smcr_link_put+0x1cc/0x1d8 [smc] smc_conn_free+0x110/0x1b0 [smc] smc_conn_abort+0x50/0x60 [smc] smc_listen_find_device+0x75c/0x790 [smc] smc_listen_work+0x368/0x8a0 [smc] process_one_work+0x1b8/0x420 worker_thread+0x158/0x510 kthread+0x114/0x118

It is caused by repeated release of LGR/link refcnt. One suspect is that smc_conn_free() is called repeatedly because some smc_conn_free() from server listening path are not protected by sock lock.

e.g.

Calls under socklock | smc_listen_work ------------------------------------------------------- lock_sock(sk) | smc_conn_abort smc_conn_free | \- smc_conn_free \- smcr_link_put | \- smcr_link_put (duplicated) release_sock(sk)

So here add sock lock protection in smc_listen_work() path, making it exclusive with other connection operations.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

December 27, 2024

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Aug 5, 2026
No patch confirmed yet.
generic

net/smc: fix LGR and link use-after-free issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2c7f14ed9c19ec0f149479d1c2842ec1f9bf76d7
generic

net/smc: fix LGR and link use-after-free issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/6f0ae06a234a78ae137064f2c89135ac078a00eb
generic

net/smc: fix LGR and link use-after-free issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/673d606683ac70bc074ca6676b938bff18635226
generic

net/smc: fix LGR and link use-after-free issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/0cf598548a6c36d90681d53c6b77d52363f2f295
generic

net/smc: fix LGR and link use-after-free issue - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f502a88fdd415647a1f2dc45fac71b9c522a052b

Patch Availability(31)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-nvidia-tegra-rt (5.15.0.1033.33) @ jammy2026-05-23ubuntu
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-21.21) @ oracular2026-05-23ubuntu
ubuntulinux-tools-lowlatency-64k (6.11.0-1011.12) @ oracular2026-05-23ubuntu
ubuntulinux-tools-oem-24.04b (6.11.0-1017.17) @ noble2026-05-23ubuntu
ubuntulinux-tools-lowlatency-hwe-24.04-edge (6.11.0-1011.12~24.04.1) @ noble2026-05-23ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.135.133) @ jammy2026-05-23ubuntu
ubuntulinux-tools-gcp-fips (5.15.0.1079.69) @ jammy2026-05-23ubuntu
ubuntulinux-tools-kvm (5.15.0.1076.72) @ jammy2026-05-23ubuntu
ubuntulinux-xilinx-zynqmp-tools-host (5.15.0-1044.48) @ jammy2026-05-23ubuntu
ubuntulinux-tools-realtime (5.15.0.1080.83) @ jammy2026-05-23ubuntu
ubuntulinux-tools-azure-fde-edge (5.15.0.1086.95~20.04.1.61) @ focal2026-05-23ubuntu
ubuntulinux-tools-raspi (6.11.0-1010.10) @ oracular2026-05-23ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.136.147~20.04.1) @ focal2026-05-23ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1024.25~22.04.1) @ jammy2026-05-23ubuntu
ubuntulinux-tools-gkeop-6.8 (6.8.0-1010.12) @ noble2026-05-23ubuntu
ubuntulinux-tools-realtime-hwe-24.04 (6.8.1-1020.21) @ noble2026-05-23ubuntu
ubuntulinux-tools-aws-edge (6.8.0-1027.29~22.04.1) @ jammy2026-05-23ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1077.83~20.04.1) @ focal2026-05-23ubuntu
ubuntulinux-tools-ibm-edge (5.15.0.1074.77~20.04.1) @ focal2026-05-23ubuntu
ubuntulinux-tools-gcp-edge (6.8.0-1028.30~22.04.1) @ jammy2026-05-23ubuntu
ubuntuoracle (5.15.0-1055) @ jammy2026-05-23ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1081.90~20.04.1) @ focal2026-05-23ubuntu
ubuntulinux-tools-azure-lts-20.04 (5.4.0.1160.153) @ focal2026-05-23ubuntu
ubuntulinux-tools-azure-fips-5.4 (5.4.0.1160.97) @ focal2026-05-23ubuntu
ubuntulinux-tools-azure-edge (5.4.0.1161.167~18.04.1) @ bionic2026-05-23ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-58.60~22.04.1) @ jammy2026-05-23ubuntu
ubuntulinux-tools-kvm-5.4 (5.4.0.1143.139) @ focal2026-05-23ubuntu
ubuntulinux-tools-ibm-lts-20.04 (5.4.0.1102.131) @ focal2026-05-23ubuntu
ubuntulinux-virtual-hwe-18.04-edge (5.4.0.227.219) @ focal2026-05-23ubuntu
ubuntulinux-tools-ibm-edge (5.4.0.1102.107~18.04.1) @ bionic2026-05-23ubuntu
linuxKernel @ 5.15.174—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(25)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 15× in last 7d / 47× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 127 total refreshes for this CVE.

  1. 2026-08-07 16:26 UTCEPSS rescore
  2. 2026-08-06 13:45 UTCEPSS rescore
  3. 2026-08-05 19:16 UTCEPSS rescore
  4. 2026-08-05 14:08 UTCEG score recompute
  5. 2026-08-05 14:08 UTCVendor advisory
  6. 2026-08-05 14:08 UTCGHSA enrichment
  7. 2026-08-04 15:08 UTCEPSS rescore
  8. 2026-08-04 11:33 UTCVendor advisory
  9. 2026-08-04 11:33 UTCGHSA enrichment
  10. 2026-08-04 11:19 UTCEG score recompute
  11. 2026-08-04 11:19 UTCVendor advisory
  12. 2026-08-04 11:19 UTCGHSA enrichment
  13. 2026-08-03 10:35 UTCEPSS rescore
  14. 2026-08-02 02:25 UTCEPSS rescore
  15. 2026-08-02 02:25 UTCEPSS rescore
  16. 2026-08-01 04:14 UTCEPSS rescore
  17. 2026-07-31 07:42 UTCOSV refresh
  18. 2026-07-30 16:26 UTCEPSS rescore
  19. 2026-07-30 16:26 UTCEPSS rescore
  20. 2026-07-30 01:29 UTCEPSS rescore
  21. 2026-07-28 15:35 UTCEPSS rescore
  22. 2026-07-26 14:53 UTCEPSS rescore
  23. 2026-07-25 14:17 UTCEPSS rescore
  24. 2026-07-25 14:17 UTCEPSS rescore
  25. 2026-07-24 14:16 UTCEPSS rescore
Show 75 more
  1. 2026-07-23 14:17 UTCEPSS rescore
  2. 2026-07-23 14:17 UTCEPSS rescore
  3. 2026-07-23 02:45 UTCEG score recompute
  4. 2026-07-22 14:07 UTCEPSS rescore
  5. 2026-07-21 15:23 UTCEPSS rescore
  6. 2026-07-20 17:07 UTCEPSS rescore
  7. 2026-07-19 14:30 UTCEPSS rescore
  8. 2026-07-19 14:30 UTCEPSS rescore
  9. 2026-07-19 02:28 UTCEPSS rescore
  10. 2026-07-19 02:28 UTCEPSS rescore
  11. 2026-07-18 10:03 UTCEPSS rescore
  12. 2026-07-16 17:02 UTCEPSS rescore
  13. 2026-07-15 16:57 UTCEPSS rescore
  14. 2026-07-15 01:59 UTCEPSS rescore
  15. 2026-07-15 01:59 UTCEPSS rescore
  16. 2026-07-13 22:29 UTCEPSS rescore
  17. 2026-07-13 15:08 UTCOSV refresh
  18. 2026-07-13 06:12 UTCEPSS rescore
  19. 2026-07-12 05:45 UTCEPSS rescore
  20. 2026-07-11 08:26 UTCEPSS rescore
  21. 2026-07-09 19:09 UTCEPSS rescore
  22. 2026-07-09 19:09 UTCEPSS rescore
  23. 2026-07-08 15:14 UTCEPSS rescore
  24. 2026-07-07 13:45 UTCEPSS rescore
  25. 2026-07-07 13:45 UTCEPSS rescore
  26. 2026-07-06 16:26 UTCEPSS rescore
  27. 2026-07-06 16:26 UTCEPSS rescore
  28. 2026-07-06 02:22 UTCEPSS rescore
  29. 2026-07-05 02:29 UTCEPSS rescore
  30. 2026-07-04 06:30 UTCEPSS rescore
  31. 2026-07-04 06:30 UTCEPSS rescore
  32. 2026-07-01 15:06 UTCEPSS rescore
  33. 2026-06-30 23:21 UTCEPSS rescore
  34. 2026-06-30 23:21 UTCEPSS rescore
  35. 2026-06-29 14:05 UTCEPSS rescore
  36. 2026-06-28 14:07 UTCEPSS rescore
  37. 2026-06-28 04:55 UTCEPSS rescore
  38. 2026-06-28 04:55 UTCEPSS rescore
  39. 2026-06-27 03:08 UTCEPSS rescore
  40. 2026-06-27 03:07 UTCEPSS rescore
  41. 2026-06-25 13:49 UTCEPSS rescore
  42. 2026-06-25 13:49 UTCEPSS rescore
  43. 2026-06-25 12:31 UTCOSV refresh
  44. 2026-06-24 14:04 UTCEPSS rescore
  45. 2026-06-24 14:04 UTCEPSS rescore
  46. 2026-06-23 21:32 UTCEPSS rescore
  47. 2026-06-22 14:25 UTCEPSS rescore
  48. 2026-06-22 14:25 UTCEPSS rescore
  49. 2026-06-21 14:56 UTCEPSS rescore
  50. 2026-06-21 14:56 UTCEPSS rescore
  51. 2026-06-21 01:59 UTCEPSS rescore
  52. 2026-06-19 19:25 UTCEPSS rescore
  53. 2026-06-19 19:25 UTCEPSS rescore
  54. 2026-06-17 17:52 UTCEPSS rescore
  55. 2026-06-16 17:52 UTCEPSS rescore
  56. 2026-06-15 17:48 UTCEPSS rescore
  57. 2026-06-14 23:17 UTCEPSS rescore
  58. 2026-06-13 22:59 UTCEPSS rescore
  59. 2026-06-13 22:59 UTCEPSS rescore
  60. 2026-06-12 23:11 UTCEPSS rescore
  61. 2026-06-12 23:11 UTCEPSS rescore
  62. 2026-06-11 13:59 UTCEPSS rescore
  63. 2026-06-11 13:59 UTCEPSS rescore
  64. 2026-06-10 22:18 UTCEPSS rescore
  65. 2026-06-10 22:18 UTCEPSS rescore
  66. 2026-06-10 13:21 UTCEPSS rescore
  67. 2026-06-08 14:16 UTCEPSS rescore
  68. 2026-06-08 14:16 UTCEPSS rescore
  69. 2026-06-08 03:28 UTCOSV refresh
  70. 2026-06-07 15:24 UTCEPSS rescore
  71. 2026-06-07 15:24 UTCEPSS rescore
  72. 2026-06-06 13:46 UTCEPSS rescore
  73. 2026-06-06 13:46 UTCEPSS rescore
  74. 2026-06-05 22:46 UTCEPSS rescore
  75. 2026-06-05 22:46 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2024-56640?
CVE-2024-56640 is a high vulnerability published on December 27, 2024. In the Linux kernel, the following vulnerability has been resolved: net/smc: fix LGR and link use-after-free issue We encountered a LGR/link use-after-free issue, which manifested as the LGR/link refcnt reaching 0 early and entering the clear process, making resource access unsafe. refcount_t:…
When was CVE-2024-56640 disclosed?
CVE-2024-56640 was first published in the National Vulnerability Database on December 27, 2024, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2024-56640 actively exploited?
CVE-2024-56640 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 53.7% of all scored CVEs.
What is the CVSS score of CVE-2024-56640?
CVE-2024-56640 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2024-56640?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2024-56640, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2024-56640

Explore →

Is Your Infrastructure Affected by CVE-2024-56640?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs