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CVE Record

CVE-2024-26841: LoongArch: Update cpu_sibling_map when disabling nonboot CPUs

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Update cpu_sibling_map when disabling nonboot CPUs Update cpu_sibling_map when disabling nonboot CPUs by defining & calling clear_cpu_sibling_map(), otherwise we get such errors on SMT systems: jump label: negative count! WARNING: CPU: 6 PID: 45 at kernel/jump_label.c:263 __static_key_slow_dec_cpuslocked+0xec/0x100 CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 pc 90000000004c302c ra 90000000004c302c tp 90000001005bc000 sp 90000001005bfd20 a0 000000000000001b a1 900000000224c278 a2 90000001005bfb58 a3 900000000224c280 a4 900000000224c278 a5 90000001005bfb50 a6 0000000000000001 a7 0000000000000001 t0 ce87a4763eb5234a t1 ce87a4763eb5234a t2 0000000000000000 t3 0000000000000000 t4 0000000000000006 t5 0000000000000000 t6 0000000000000064 t7 0000000000001964 t8 000000000009ebf6 u0 9000000001f2a068 s9 0000000000000000 s0 900000000246a2d8 s1 ffffffffffffffff s2 ffffffffffffffff s3 90000000021518c0 s4 0000000000000040 s5 9000000002151058 s6 9000000009828e40 s7 00000000000000b4 s8 0000000000000006 ra: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 ERA: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1c (LIE=2-4,10-12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014d000 (Loongson-64bit, Loongson-3A6000-HV) CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 Stack : 0000000000000000 900000000203f258 900000000179afc8 90000001005bc000 90000001005bf980 0000000000000000 90000001005bf988 9000000001fe0be0 900000000224c280 900000000224c278 90000001005bf8c0 0000000000000001 0000000000000001 ce87a4763eb5234a 0000000007f38000 90000001003f8cc0 0000000000000000 0000000000000006 0000000000000000 4c206e6f73676e6f 6f4c203a656d616e 000000000009ec99 0000000007f38000 0000000000000000 900000000214b000 9000000001fe0be0 0000000000000004 0000000000000000 0000000000000107 0000000000000009 ffffffffffafdabe 00000000000000b4 0000000000000006 90000000004c302c 9000000000224528 00005555939a0c7c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c ... Call Trace: [<9000000000224528>] show_stack+0x48/0x1a0 [<900000000179afc8>] dump_stack_lvl+0x78/0xa0 [<9000000000263ed0>] __warn+0x90/0x1a0 [<90000000017419b8>] report_bug+0x1b8/0x280 [<900000000179c564>] do_bp+0x264/0x420 [<90000000004c302c>] __static_key_slow_dec_cpuslocked+0xec/0x100 [<90000000002b4d7c>] sched_cpu_deactivate+0x2fc/0x300 [<9000000000266498>] cpuhp_invoke_callback+0x178/0x8a0 [<9000000000267f70>] cpuhp_thread_fun+0xf0/0x240 [<90000000002a117c>] smpboot_thread_fn+0x1dc/0x2e0 [<900000000029a720>] kthread+0x140/0x160 [<9000000000222288>] ret_from_kernel_thread+0xc/0xa4

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel issue affecting LoongArch systems. When nonboot CPUs are disabled on SMT systems, the kernel may keep stale CPU sibling information and trigger internal warnings. The source bundle does not show remote exploitation, privilege escalation, or data theft.

Executive priority

Treat as targeted kernel maintenance for LoongArch infrastructure, not broad emergency response. Prioritize patching if the organization operates LoongArch SMT systems or relies on CPU hotplug/offlining. Evidence is insufficient to justify enterprise-wide crisis handling.

Technical view

The LoongArch CPU hotplug path failed to update cpu_sibling_map when disabling nonboot CPUs. On SMT systems this can lead to inconsistent scheduler/static-key accounting and a “jump label: negative count!” warning during CPU deactivation. Stable kernel commits add clear_cpu_sibling_map handling.

Likely exposure

Exposure appears limited to Linux systems running affected LoongArch kernels, especially SMT-capable Loongson/LoongArch hosts where CPUs are offlined or hotplugged. General x86, Arm, and non-LoongArch fleets are not indicated as affected by the provided sources.

Exploitation context

The provided sources do not report active exploitation, public exploit code, or KEV listing. Evidence describes a kernel warning during CPU hotplug/offlining, not an attacker-driven exploit path. Operational impact is plausible, but security impact is not fully characterized in the bundle.

Researcher notes

Key uncertainty is impact severity. The CVE record gives no CVSS, CWE, or exploitability detail. Analysis should focus on LoongArch CPU hotplug state handling, scheduler/static-key interactions, and whether warning conditions can cause denial of service in real deployments.

Mitigation direction

  • Apply vendor kernel updates that include the referenced stable LoongArch fixes.
  • Prioritize LoongArch SMT hosts and systems using CPU hotplug or CPU offlining.
  • Check distribution advisories for exact fixed package versions before deployment.
  • Where feasible before patching, minimize nonboot CPU offlining on affected LoongArch SMT systems.

Validation and detection

  • Inventory LoongArch Linux systems and record running kernel versions.
  • Compare kernels against vendor advisories and the referenced stable commits.
  • Review kernel logs for “jump label: negative count!” during CPU deactivation.
  • Confirm patched kernels no longer reproduce the warning during approved CPU hotplug testing.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2024-26841 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxfa96b57c149061f71a70bd6582d995f6424fbbf4, fa96b57c149061f71a70bd6582d995f6424fbbf4, fa96b57c149061f71a70bd6582d995f6424fbbf4unaffected
LinuxLinux5.19, 0, 6.6.19, 6.7.7, 6.8affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.