Service interruption via unaligned online filesystem resize
Published Jun 18, 2025 · Updated May 11, 2026
Improper quantity validation in Linux kernel ext4 allows local users to interrupt filesystem service through an unaligned online resize. The ext4_resize_fs path uses an unaligned requested block count, so its final growth iteration computes a negative amount, reaches BUG_ON, and corrupts the in-memory superblock. Triggering the flaw requires local access sufficient to initiate online resize on an ext4 bigalloc filesystem; the documented consequence is a kernel fault and transient in-memory corruption.
Summary
What happened
Improper quantity validation in Linux kernel ext4 allows local users to interrupt filesystem service through an unaligned online resize. The ext4_resize_fs path uses an unaligned requested block count, so its final growth iteration computes a negative amount, reaches BUG_ON, and corrupts the in-memory superblock. Triggering the flaw requires local access sufficient to initiate online resize on an ext4 bigalloc filesystem; the documented consequence is a kernel fault and transient in-memory corruption.
The record
- CVE
- CVE-2022-50020
- Published
- Jun 18, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-1284, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 18, 2025CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=4.15
- Affected versionversion=d77147ff443b255d82c907a632c825b2cc610b10 <0082e99a9074ff88eff729c70c93454c8588d8e1
- Affected versionversion=d77147ff443b255d82c907a632c825b2cc610b10 <69cb8e9d8cd97cdf5e293b26d70a9dee3e35e6bd
- Affected versionversion=d77147ff443b255d82c907a632c825b2cc610b10 <72b850a2a996f72541172e7cf686d54a2b29bcd8
- Affected versionversion=d77147ff443b255d82c907a632c825b2cc610b10 <7bdfb01fc5f6b3696728aeb527c50386e0ee09a1
- Affected versionversion=d77147ff443b255d82c907a632c825b2cc610b10 <80288883294c5b4ed18bae0d8bd9c4a12f297074
- Affected versionversion=d77147ff443b255d82c907a632c825b2cc610b10 <a6805b3dcf5cd41f2ae3a03dca43411135b99849
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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