Local system crash via truncated ext4 allocation
Published Feb 26, 2025 · Updated May 23, 2026
Reachable assertion in the Linux kernel ext4 allocator allows local users to crash the system through crafted filesystem activity. After request-size truncation, ext4_mb_normalize_request calculates the wrong block-group start, allowing ext4_mb_use_inode_pa to produce a nonpositive extent length that reaches BUG_ON in ext4_mb_mark_diskspace_used. The path requires local activity on a mounted ext4 filesystem with a small block-group size and interrupts the entire system when the kernel assertion fires.
Summary
What happened
Reachable assertion in the Linux kernel ext4 allocator allows local users to crash the system through crafted filesystem activity. After request-size truncation, ext4_mb_normalize_request calculates the wrong block-group start, allowing ext4_mb_use_inode_pa to produce a nonpositive extent length that reaches BUG_ON in ext4_mb_mark_diskspace_used. The path requires local activity on a mounted ext4 filesystem with a small block-group size and interrupts the entire system when the kernel assertion fires.
The record
- CVE
- CVE-2022-49708
- Published
- Feb 26, 2025
- Updated
- May 23, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-617, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- May 23, 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=3.10.107 <3.11
- Affected versionversion=3.12.72 <3.13
- Affected versionversion=3.16.44 <3.17
- Affected versionversion=3.2.89 <3.3
- Affected versionversion=37cf4ab1ba60c30ca9fd0fe3b9993b24cb87886a
- Affected versionversion=4.10.2 <4.11
- Affected versionversion=4.11
- Affected versionversion=4.1.40 <4.2
- Affected versionversion=4.4.53 <4.5
- Affected versionversion=4.9.14 <4.9.320
- Affected versionversion=75f37dab088eb84ff25a49e59371f01ea3f44aa7
- Affected versionversion=8774c73cf6963310395823ed7077ea12943ea0f3
- Affected versionversion=98f58e05231f835dfb09359e3b5e3a886fe8f189
- Affected versionversion=c1664e9bcf6291c0ceb8599f57c8cf493526abe6
- Affected versionversion=c4fbdc0124799f1772f4d886b7f2e1a6f881d195
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <5707d721d1819db57dba57b1d4623034fcb32047
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <6fdaf31ad5f3d3afab744dfd9a8b0d9142aa881f
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <887a3e9ad4b8309a2266bce7ae749b2bf1f7a687
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <90f0f9d45dff0128c0fca0d2358c4153b024afa6
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <a08f789d2ab5242c07e716baf9a835725046be89
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <a37c1359714da42517dd19d36fc3c4d17edba832
- Affected versionversion=cd648b8a8fd5071d232242d5ee7ee3c0815776af <a6b31616e5afe1d3972cb0682a373e50597faf5c
- Affected versionversion=f213db429b883a2d5403de0b1ce92fb7d7ee979e
- Affected versionversion=fc6c2da174edd7a7b760b12c60d432d300e05cca <6880fb2e64331b9fdc85d3f32b1d7e81ad8703f1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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