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Fencer Vulns
critical 9.8

CVE-2024-56718 in the critical feed json

net/smc: protect link down work from execute after lgr freed

published 2024-12-29 22 mo ago modified 2026-08-05 3 mo ago also EUVD-2024-53366

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

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

net/smc: protect link down work from execute after lgr freed

link down work may be scheduled before lgr freed but execute after lgr freed, which may result in crash. So it is need to hold a reference before shedule link down work, and put the reference after work executed or canceled.

The relevant crash call stack as follows: list_del corruption. prev->next should be ffffb638c9c0fe20, but was 0000000000000000 ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:51! invalid opcode: 0000 [#1] SMP NOPTI CPU: 6 PID: 978112 Comm: kworker/6:119 Kdump: loaded Tainted: G #1 Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 2221b89 04/01/2014 Workqueue: events smc_link_down_work [smc] RIP: 0010:__list_del_entry_valid.cold+0x31/0x47 RSP: 0018:ffffb638c9c0fdd8 EFLAGS: 00010086 RAX: 0000000000000054 RBX: ffff942fb75e5128 RCX: 0000000000000000 RDX: ffff943520930aa0 RSI: ffff94352091fc80 RDI: ffff94352091fc80 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffb638c9c0fc38 R10: ffffb638c9c0fc30 R11: ffffffffa015eb28 R12: 0000000000000002 R13: ffffb638c9c0fe20 R14: 0000000000000001 R15: ffff942f9cd051c0 FS: 0000000000000000(0000) GS:ffff943520900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f25214000 CR3: 000000025fbae004 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: rwsem_down_write_slowpath+0x17e/0x470 smc_link_down_work+0x3c/0x60 [smc] process_one_work+0x1ac/0x350 worker_thread+0x49/0x2f0 ? rescuer_thread+0x360/0x360 kthread+0x118/0x140 ? __kthread_bind_mask+0x60/0x60 ret_from_fork+0x1f/0x30

Patch / fix

  • Linux Linux 6.1.122, 6.6.68, 6.12.7, 6.13
  • linux Debian 12 6.1.123-1
  • linux Debian 14, Debian 13 6.12.8-1

debian advisories DEBIAN-CVE-2024-56718

  • linux Ubuntu 24.04 LTS 6.8.0-60.63
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1029.31
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1030.32
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1025.29
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1026.26
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1029.34
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1012.14
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1028.32

ubuntu advisories UBUNTU-CVE-2024-56718

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.3.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.3.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1

suse advisories SUSE-SU-2025:01967-1SUSE-SU-2025:01951-1SUSE-SU-2025:01919-1SUSE-SU-2025:20192-1SUSE-SU-2025:20270-1SUSE-SU-2025:20190-1

  • kernel Azure Linux 3.0 6.6.76.1-1

azure linux advisories AZL-55419

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-56718 updated cvss 5.9

kernel: net/smc: protect link down work from execute after lgr freed

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.