System crash via incomplete fork address space
Published Nov 9, 2024 · Updated May 11, 2026
Race condition in Linux kernel 6.8 through 6.11.6 allows local users to crash the system by triggering a failed fork with userfaultfd. dup_userfaultfd_complete() unconditionally reports UFFD_EVENT_FORK after an error, exposing a child address space whose maple-tree entries can remain inconsistent. Exploitation requires local access, a registered userfaultfd fork handler, and success in a high-complexity fork-error race.
Summary
What happened
Race condition in Linux kernel 6.8 through 6.11.6 allows local users to crash the system by triggering a failed fork with userfaultfd. dup_userfaultfd_complete() unconditionally reports UFFD_EVENT_FORK after an error, exposing a child address space whose maple-tree entries can remain inconsistent. Exploitation requires local access, a registered userfaultfd fork handler, and success in a high-complexity fork-error race.
The record
- CVE
- CVE-2024-50220
- Published
- Nov 9, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-367
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 9, 2024CVE 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?
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- Affected versionversion=6.8
- Affected versionversion=d2406291483775ecddaee929231a39c70c08fda2 <92b472945dbf8abc020e9259c0088026f7027dfc
- Affected versionversion=d2406291483775ecddaee929231a39c70c08fda2 <f64e67e5d3a45a4a04286c47afade4b518acd47b
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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