CVE-2022-48920

Kernel log flooding via unlocked Btrfs writeback

Published Aug 22, 2024 · Updated May 11, 2026

Improper locking in Linux before 5.17 allows local users to flood kernel logs through repeated Btrfs transaction commits. With flushoncommit enabled, btrfs_commit_transaction calls writeback_inodes_sb without holding sb->s_umount, triggering a WARN on nearly every commit. Local access and a Btrfs filesystem mounted with flushoncommit are required; repeated warnings consume dmesg and syslog capacity.

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

What happened

Improper locking in Linux before 5.17 allows local users to flood kernel logs through repeated Btrfs transaction commits. With flushoncommit enabled, btrfs_commit_transaction calls writeback_inodes_sb without holding sb->s_umount, triggering a WARN on nearly every commit. Local access and a Btrfs filesystem mounted with flushoncommit are required; repeated warnings consume dmesg and syslog capacity.

The record

CVE
CVE-2022-48920
Published
Aug 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 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=4.15
  2. Affected versionversion=ce8ea7cc6eb3139f4c730d647325e69354159b0f <850a77c999b81dd2724efd2684068d6f90db8c16
  3. Affected versionversion=ce8ea7cc6eb3139f4c730d647325e69354159b0f <a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa
  4. Affected versionversion=ce8ea7cc6eb3139f4c730d647325e69354159b0f <e4d044dbffcd570351f21c747fc77ff90aed7f2e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.15; version=ce8ea7cc6eb3139f4c730d647325e69354159b0f <850a77c999b81dd2724efd2684068d6f90db8c16; version=ce8ea7cc6eb3139f4c730d647325e69354159b0f <a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa; version=ce8ea7cc6eb3139f4c730d647325e69354159b0f <e4d044dbffcd570351f21c747fc77ff90aed7f2e

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-667Improper Locking

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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