CVE-2022-50620

Kernel crash via stale discard-thread pointer

Published Dec 8, 2025 · Updated May 11, 2026

NULL pointer dereference in Linux kernel F2FS allows attackers to crash the kernel during affected file-system teardown. The f2fs_start_discard_thread() error path leaves dcc->f2fs_issue_discard pointing at an invalid task, which kthread_stop() later dereferences. Reachability requires F2FS teardown after discard-thread startup fails, and the resulting fault interrupts the host.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Linux kernel F2FS allows attackers to crash the kernel during affected file-system teardown. The f2fs_start_discard_thread() error path leaves dcc->f2fs_issue_discard pointing at an invalid task, which kthread_stop() later dereferences. Reachability requires F2FS teardown after discard-thread startup fails, and the resulting fault interrupts the host.

The record

CVE
CVE-2022-50620
Published
Dec 8, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 8, 2025CVE 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?

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  1. Affected versionversion=4d67490498acb4ffcef5ba7bc44990d46e66a44c <865bb7b5a7deeb0e5afbd82381d52d38825dc64d
  2. Affected versionversion=4d67490498acb4ffcef5ba7bc44990d46e66a44c <91586ce0d39a05f88795aa8814fb99b1387236b3
  3. Affected versionversion=4d67490498acb4ffcef5ba7bc44990d46e66a44c <a3e517a6ba695d683ee63615e1ea6e6b4c7d2732
  4. Affected versionversion=4d67490498acb4ffcef5ba7bc44990d46e66a44c <ae6c960a82c52c3bda5adc82d90643d6c12d308e
  5. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4d67490498acb4ffcef5ba7bc44990d46e66a44c <865bb7b5a7deeb0e5afbd82381d52d38825dc64d; version=4d67490498acb4ffcef5ba7bc44990d46e66a44c <91586ce0d39a05f88795aa8814fb99b1387236b3; version=4d67490498acb4ffcef5ba7bc44990d46e66a44c <a3e517a6ba695d683ee63615e1ea6e6b4c7d2732; version=4d67490498acb4ffcef5ba7bc44990d46e66a44c <ae6c960a82c52c3bda5adc82d90643d6c12d308e; version=5.15

Published CVSS scores

No CVSS assessment is available in this record.

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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