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CVE Record

CVE-2024-44938: jfs: Fix shift-out-of-bounds in dbDiscardAG

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix shift-out-of-bounds in dbDiscardAG When searching for the next smaller log2 block, BLKSTOL2() returned 0, causing shift exponent -1 to be negative. This patch fixes the issue by exiting the loop directly when negative shift is found.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2024-44938 is a Linux kernel JFS filesystem bug. A kernel calculation could produce a negative shift while discarding allocation-group blocks. The public record says this has been fixed upstream, but gives no CVSS score and no evidence of active exploitation.

Executive priority

Treat this as a normal kernel maintenance item unless JFS is widely used in critical systems. Prioritize patching through standard kernel update windows, and escalate only if vendor advisories add severity, exploitability, or active exploitation evidence.

Technical view

The flaw is in JFS dbDiscardAG. During the search for the next smaller log2 block, BLKSTOL2() could return 0, making the shift exponent negative. Stable kernel patches resolve it by leaving the loop when that negative shift condition is found.

Likely exposure

Exposure is most relevant to Linux systems running affected kernels where JFS is available or used. The source bundle lists Linux as affected and includes stable kernel and Debian LTS references; exact exposure depends on the distribution kernel build and backports.

Exploitation context

The provided sources do not report public exploitation, weaponization, or CISA KEV listing. The practical attack path and required local or remote preconditions are not described in the bundle, so exploitation likelihood cannot be assessed from these sources alone.

Researcher notes

Evidence is limited to the CVE description, stable kernel commits, and Debian LTS references. No CWE, CVSS, exploit status, or detailed trigger conditions are provided. Avoid assuming affected downstream versions without checking distribution backport metadata.

Mitigation direction

  • Apply vendor kernel updates that include the referenced JFS stable fixes.
  • Review Debian LTS advisories if running Debian-based long-term-support systems.
  • Check distribution security guidance for backported fixed kernel package versions.
  • Reduce or avoid JFS use where operationally unnecessary until patched.

Validation and detection

  • Inventory Linux kernels and map them to vendor fixed package versions.
  • Confirm whether JFS filesystems or the jfs module are present or used.
  • Verify installed kernels include the referenced stable commits or distro backports.
  • Track vendor advisories for corrected affected-version ranges and severity scoring.
Prepared
Confidence
medium
Sources
10

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-2024-44938 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
9Source 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
LinuxLinuxb40c2e665cd552eae5fbdbb878bc29a34357668e, b40c2e665cd552eae5fbdbb878bc29a34357668e, b40c2e665cd552eae5fbdbb878bc29a34357668e, b40c2e665cd552eae5fbdbb878bc29a34357668e, b40c2e665cd552eae5fbdbb878bc29a34357668e, b40c2e665cd552eae5fbdbb878bc29a34357668eunaffected
LinuxLinux3.7, 0, 5.10.237, 5.15.181, 6.1.107, 6.6.47, 6.10.6, 6.11affected
Weakness

CWE details

No CWE listed

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