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CVE Record

CVE-2021-47098: hwmon: (lm90) Prevent integer overflow/underflow in hysteresis calculations

In the Linux kernel, the following vulnerability has been resolved: hwmon: (lm90) Prevent integer overflow/underflow in hysteresis calculations Commit b50aa49638c7 ("hwmon: (lm90) Prevent integer underflows of temperature calculations") addressed a number of underflow situations when writing temperature limits. However, it missed one situation, seen when an attempt is made to set the hysteresis value to MAX_LONG and the critical temperature limit is negative. Use clamp_val() when setting the hysteresis temperature to ensure that the provided value can never overflow or underflow.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue affects the lm90 hardware monitoring driver. A temperature hysteresis value could overflow or underflow during calculation under specific input conditions. Public sources do not state business impact, exploitability, or a CVSS score, so urgency should be based on kernel exposure and vendor guidance.

Executive priority

Treat this as a kernel hygiene item with unknown severity. It is not listed in KEV and the provided sources do not show exploitation, but kernel issues should be remediated through normal patch cycles where affected systems exist.

Technical view

The flaw is in hwmon/lm90 hysteresis temperature handling. A prior underflow fix missed a case involving MAX_LONG hysteresis input with a negative critical temperature limit. The kernel fix clamps the hysteresis value to prevent arithmetic overflow or underflow.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions or commits with the lm90 hardware monitoring driver relevant to the platform. The source bundle identifies Linux kernel version ranges around 5.14, 5.15.12, and 5.16, but exact deployed exposure requires vendor kernel mapping.

Exploitation context

The source bundle does not report active exploitation, public exploit availability, KEV listing, required privileges, or practical impact. It only describes a specific invalid-value calculation path in the kernel driver.

Researcher notes

Evidence is narrow: the CVE text describes the arithmetic flaw and clamp-based fix, but not impact, reachability, privilege requirements, or crash behavior. Researchers should validate exposure against exact kernel source, config, driver use, and distribution backports.

Mitigation direction

  • Check Linux distribution advisories for CVE-2021-47098 kernel updates.
  • Upgrade affected kernels to a vendor-supported fixed build.
  • Prioritize systems using lm90-compatible hardware monitoring paths.
  • Avoid direct wrangler-style assumptions; follow vendor kernel backport status.
  • Track the referenced stable kernel fixes in asset remediation notes.

Validation and detection

  • Inventory Linux kernel versions across managed hosts.
  • Map distribution kernel builds to the referenced upstream stable fixes.
  • Check whether lm90 hardware monitoring support is loaded or compiled.
  • Review vendor advisories for backported fixes under CVE-2021-47098.
  • Confirm remediation with package metadata, not upstream version alone.
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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-47098 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
3Source 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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxb50aa49638c7e12abf4ecc483f4e928c5cccc1b0, b50aa49638c7e12abf4ecc483f4e928c5cccc1b0unaffected
LinuxLinux5.14, 0, 5.15.12, 5.16affected
Weakness

CWE details

No CWE listed

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