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CVE Record

CVE-2022-50223: LoongArch: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK

In the Linux kernel, the following vulnerability has been resolved: LoongArch: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK When CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS is selected, cpu_max_bits_warn() generates a runtime warning similar as below while we show /proc/cpuinfo. Fix this by using nr_cpu_ids (the runtime limit) instead of NR_CPUS to iterate CPUs. [ 3.052463] ------------[ cut here ]------------ [ 3.059679] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:108 show_cpuinfo+0x5e8/0x5f0 [ 3.070072] Modules linked in: efivarfs autofs4 [ 3.076257] CPU: 0 PID: 1 Comm: systemd Not tainted 5.19-rc5+ #1052 [ 3.084034] Hardware name: Loongson Loongson-3A5000-7A1000-1w-V0.1-CRB/Loongson-LS3A5000-7A1000-1w-EVB-V1.21, BIOS Loongson-UDK2018-V2.0.04082-beta7 04/27 [ 3.099465] Stack : 9000000100157b08 9000000000f18530 9000000000cf846c 9000000100154000 [ 3.109127] 9000000100157a50 0000000000000000 9000000100157a58 9000000000ef7430 [ 3.118774] 90000001001578e8 0000000000000040 0000000000000020 ffffffffffffffff [ 3.128412] 0000000000aaaaaa 1ab25f00eec96a37 900000010021de80 900000000101c890 [ 3.138056] 0000000000000000 0000000000000000 0000000000000000 0000000000aaaaaa [ 3.147711] ffff8000339dc220 0000000000000001 0000000006ab4000 0000000000000000 [ 3.157364] 900000000101c998 0000000000000004 9000000000ef7430 0000000000000000 [ 3.167012] 0000000000000009 000000000000006c 0000000000000000 0000000000000000 [ 3.176641] 9000000000d3de08 9000000001639390 90000000002086d8 00007ffff0080286 [ 3.186260] 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c [ 3.195868] ... [ 3.199917] Call Trace: [ 3.203941] [<90000000002086d8>] show_stack+0x38/0x14c [ 3.210666] [<9000000000cf846c>] dump_stack_lvl+0x60/0x88 [ 3.217625] [<900000000023d268>] __warn+0xd0/0x100 [ 3.223958] [<9000000000cf3c90>] warn_slowpath_fmt+0x7c/0xcc [ 3.231150] [<9000000000210220>] show_cpuinfo+0x5e8/0x5f0 [ 3.238080] [<90000000004f578c>] seq_read_iter+0x354/0x4b4 [ 3.245098] [<90000000004c2e90>] new_sync_read+0x17c/0x1c4 [ 3.252114] [<90000000004c5174>] vfs_read+0x138/0x1d0 [ 3.258694] [<90000000004c55f8>] ksys_read+0x70/0x100 [ 3.265265] [<9000000000cfde9c>] do_syscall+0x7c/0x94 [ 3.271820] [<9000000000202fe4>] handle_syscall+0xc4/0x160 [ 3.281824] ---[ end trace 8b484262b4b8c24c ]---

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel issue limited to LoongArch CPU information handling. Reading /proc/cpuinfo can trigger a kernel warning under specific debug and CPU mask configurations. The provided sources do not show data theft, privilege escalation, remote attack, or active exploitation.

Executive priority

Treat this as routine kernel maintenance unless LoongArch systems are operationally important or logs show instability. There is no source-backed evidence of active exploitation or high-impact security abuse.

Technical view

LoongArch show_cpuinfo iterated CPUs using NR_CPUS instead of nr_cpu_ids when CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS were enabled. That could trigger cpu_max_bits_warn() during /proc/cpuinfo reads. The fix changes iteration to the runtime CPU limit.

Likely exposure

Exposure appears limited to Linux systems on LoongArch hardware with the relevant kernel versions and configuration options enabled. General Linux deployments on other architectures are not indicated as affected by the provided sources.

Exploitation context

The bundle marks KEV as false and provides no cited evidence of exploitation. The described behavior is a runtime warning during /proc/cpuinfo access, not an exploit path or security boundary bypass in the supplied evidence.

Researcher notes

The core defect is bounds selection in CPU mask iteration for LoongArch cpuinfo display. Evidence is narrow: affected metadata, warning trace, and two stable commit references. No CVSS, CWE, exploit status, or distribution-specific advisories are provided.

Mitigation direction

  • Review Linux vendor guidance for your distribution and LoongArch kernel packages.
  • Update to a kernel containing the referenced stable fixes where applicable.
  • Prioritize LoongArch systems running affected 5.19-era or 6.0 kernel metadata entries.
  • If patching is delayed, monitor kernel logs for repeated cpuinfo warnings.

Validation and detection

  • Inventory LoongArch Linux systems and their running kernel versions.
  • Check whether CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS are enabled.
  • Confirm downstream kernel packages include the referenced stable commits.
  • Review dmesg or system logs for show_cpuinfo cpu_max_bits_warn messages.
Prepared
Confidence
medium
Sources
4

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-2022-50223 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
0ADP providers
3Source links

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

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Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxfa96b57c149061f71a70bd6582d995f6424fbbf4, fa96b57c149061f71a70bd6582d995f6424fbbf4unaffected
LinuxLinux5.19, 0, 5.19.2, 6.0affected
Weakness

CWE details

No CWE listed

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