CVE-2024-56582

Kernel crash via encoded-read completion race

Published Dec 27, 2024 · Updated May 11, 2026

Use-after-free in Linux kernel Btrfs 5.18 through 6.12.3 allows local users to crash the kernel through an encoded-read race. The btrfs_encoded_read_endio() callback uses atomic_dec_return() to decrement and test a pending-I/O counter in separate x86 instructions, allowing one completion to free the encoded-read context while another wakes its freed wait queue. Reaching the faulty encoded-I/O path requires CAP_SYS_ADMIN and a Btrfs workload with concurrent encoded reads; successful triggering produces a kernel fault and service interruption.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel Btrfs 5.18 through 6.12.3 allows local users to crash the kernel through an encoded-read race. The btrfs_encoded_read_endio() callback uses atomic_dec_return() to decrement and test a pending-I/O counter in separate x86 instructions, allowing one completion to free the encoded-read context while another wakes its freed wait queue. Reaching the faulty encoded-I/O path requires CAP_SYS_ADMIN and a Btrfs workload with concurrent encoded reads; successful triggering produces a kernel fault and service interruption.

The record

CVE
CVE-2024-56582
Published
Dec 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 27, 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=1881fba89bd5dcd364d2e1bf561912a90a11c21a <05b36b04d74a517d6675bf2f90829ff1ac7e28dc
  2. Affected versionversion=1881fba89bd5dcd364d2e1bf561912a90a11c21a <6228f13f1996a4feb9b601d6644bf0bfe03671dd
  3. Affected versionversion=1881fba89bd5dcd364d2e1bf561912a90a11c21a <a40de0330af4fb7bc6b354250c24f294f8b826a0
  4. Affected versionversion=1881fba89bd5dcd364d2e1bf561912a90a11c21a <f8a5129e4a9fc3f6aa3f137513253b51b31b94d4
  5. Affected versionversion=5.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=1881fba89bd5dcd364d2e1bf561912a90a11c21a <05b36b04d74a517d6675bf2f90829ff1ac7e28dc; version=1881fba89bd5dcd364d2e1bf561912a90a11c21a <6228f13f1996a4feb9b601d6644bf0bfe03671dd; version=1881fba89bd5dcd364d2e1bf561912a90a11c21a <a40de0330af4fb7bc6b354250c24f294f8b826a0; version=1881fba89bd5dcd364d2e1bf561912a90a11c21a <f8a5129e4a9fc3f6aa3f137513253b51b31b94d4; version=5.18

Published CVSS scores

7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Endpoint Denial of Service: Application 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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