CVE-2024-44938

Service interruption via negative shift in dbDiscardAG

Published Aug 26, 2024 · Updated May 11, 2026

Shift-out-of-bounds in the JFS block allocator in Linux allows local users to interrupt kernel availability through JFS block discard. In dbDiscardAG, BLKSTOL2(nblocks) can return zero, and the code subtracts one before using the result as the left-shift exponent. Local low-privileged access is required; the negative exponent affects availability without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Shift-out-of-bounds in the JFS block allocator in Linux allows local users to interrupt kernel availability through JFS block discard. In dbDiscardAG, BLKSTOL2(nblocks) can return zero, and the code subtracts one before using the result as the left-shift exponent. Local low-privileged access is required; the negative exponent affects availability without reported data disclosure or modification.

The record

CVE
CVE-2024-44938
Published
Aug 26, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.7
  2. Affected versionversion=b40c2e665cd552eae5fbdbb878bc29a34357668e <234e6ea0855cdb5673d54ecaf7dc5c78f3e84630
  3. Affected versionversion=b40c2e665cd552eae5fbdbb878bc29a34357668e <4de2c04c3acd5b84f50b0d2f8f09e9b2f42374b9
  4. Affected versionversion=b40c2e665cd552eae5fbdbb878bc29a34357668e <7063b80268e2593e58bee8a8d709c2f3ff93e2f2
  5. Affected versionversion=b40c2e665cd552eae5fbdbb878bc29a34357668e <bb7c605a754823b86dd74f6537ccb9d38a9dec5a
  6. Affected versionversion=b40c2e665cd552eae5fbdbb878bc29a34357668e <bd04a149e3a29e7f71b7956ed41dba34e42d539e
  7. Affected versionversion=b40c2e665cd552eae5fbdbb878bc29a34357668e <f650148b43949ca9e37e820804bb6026fff404f3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.7; version=b40c2e665cd552eae5fbdbb878bc29a34357668e <234e6ea0855cdb5673d54ecaf7dc5c78f3e84630; version=b40c2e665cd552eae5fbdbb878bc29a34357668e <4de2c04c3acd5b84f50b0d2f8f09e9b2f42374b9; version=b40c2e665cd552eae5fbdbb878bc29a34357668e <7063b80268e2593e58bee8a8d709c2f3ff93e2f2; version=b40c2e665cd552eae5fbdbb878bc29a34357668e <bb7c605a754823b86dd74f6537ccb9d38a9dec5a; version=b40c2e665cd552eae5fbdbb878bc29a34357668e <bd04a149e3a29e7f71b7956ed41dba34e42d539e; version=b40c2e665cd552eae5fbdbb878bc29a34357668e <f650148b43949ca9e37e820804bb6026fff404f3

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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