Kernel panic via ext4 unmount race
Published Dec 30, 2025 · Updated Dec 30, 2025
A race in Linux ext4 extended-attribute handling allows local users to trigger a kernel panic during filesystem unmount. The ext4_xattr_inode_create path can continue after unmount clears s_root, then dereference that null root while expanding extended-attribute storage. Triggering the crash requires local control of an ext4 filesystem and a successful race between extended-attribute expansion and unmount processing.
Summary
What happened
A race in Linux ext4 extended-attribute handling allows local users to trigger a kernel panic during filesystem unmount. The ext4_xattr_inode_create path can continue after unmount clears s_root, then dereference that null root while expanding extended-attribute storage. Triggering the crash requires local control of an ext4 filesystem and a successful race between extended-attribute expansion and unmount processing.
The record
- CVE
- CVE-2023-54305
- Published
- Dec 30, 2025
- Updated
- Dec 30, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Dec 30, 2025CVE publishedPublication date reported by the CVE source.
- Dec 30, 2025Record 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.
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <05cbf6ddd9847c7b4f0662c048f195b09405a9d0
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0dc0fa313bb4e86382a3e7125429710d44383196
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <116008ada3d0de4991099edaf6b8c2e9cd6f225a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <21f6a80d9234422e2eb445734b22c78fc5bf6719
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a458a8c1d1fc4e10a1813786132b09a3863ad3f2
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a92b67e768bde433b9385cde56c09deb58db269e
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aedea161d031502a423ed1c7597754681a4f8cda
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f31173c19901a96bb2ebf6bcfec8a08df7095c91
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- syzbot ext4_xattr_set_entry C reproducerproof of concept · demonstrated
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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