Service interruption via leaked ext4 mount allocations
Published Feb 26, 2025 · Updated May 11, 2026
Memory leak in ext4 in Linux kernel 5.17 before 5.17.14 and 5.18 before 5.18.3 allows local users to interrupt service. When parse_apply_sb_mount_options() fails after allocating ext4_fs_context members such as s_qf_names, its error path frees only the context instead of invoking ext4_fc_free(), leaving nested allocations unreleased. Triggering the leak requires local access and an ext4 filesystem whose stored mount options force parsing to fail; repeated triggers can exhaust kernel memory and interrupt service.
Summary
What happened
Memory leak in ext4 in Linux kernel 5.17 before 5.17.14 and 5.18 before 5.18.3 allows local users to interrupt service. When parse_apply_sb_mount_options() fails after allocating ext4_fs_context members such as s_qf_names, its error path frees only the context instead of invoking ext4_fc_free(), leaving nested allocations unreleased. Triggering the leak requires local access and an ext4 filesystem whose stored mount options force parsing to fail; repeated triggers can exhaust kernel memory and interrupt service.
The record
- CVE
- CVE-2022-49408
- Published
- Feb 26, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-401, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 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=5.17
- Affected versionversion=7edfd85b1ffd36593011dec96ab395912a340418 <9ea3e6168948189cec31d0678d2b55b395f88491
- Affected versionversion=7edfd85b1ffd36593011dec96ab395912a340418 <c069db76ed7b681c69159f44be96d2137e9ca989
- Affected versionversion=7edfd85b1ffd36593011dec96ab395912a340418 <f92ded66e9d0aa20b883a2a5183973abc8f41815
What conditions does exploitation require?
What is affected?
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
- Linux ext4 kmemleak 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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