Local privilege escalation via SLUB freelist corruption
Published Feb 26, 2025 · Updated Aug 5, 2026
Use-after-free in the SLUB allocator in Linux 3.1 and later affected releases allows local users to gain kernel privileges through a race. During slab deactivation, two __slab_alloc() paths replace c->slab without incrementing the transaction ID, so a preempted do_slab_free() can commit a stale freelist update against the wrong slab. An unprivileged local user must race allocations and frees on the same CPU and kmem_cache; success enables kernel memory disclosure, write primitives, privilege escalation, or a kernel crash.
Summary
What happened
Use-after-free in the SLUB allocator in Linux 3.1 and later affected releases allows local users to gain kernel privileges through a race. During slab deactivation, two __slab_alloc() paths replace c->slab without incrementing the transaction ID, so a preempted do_slab_free() can commit a stale freelist update against the wrong slab. An unprivileged local user must race allocations and frees on the same CPU and kmem_cache; success enables kernel memory disclosure, write primitives, privilege escalation, or a kernel crash.
The record
- CVE
- CVE-2022-49700
- Published
- Feb 26, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=03e404af26dc2ea0d278d7a342de0aab394793ce <0515cc9b6b24877f59b222ade704bfaa42caa2a6
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <197e257da473c725dfe47759c3ee02f2398d8ea5
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <308c6d0e1f200fd26c71270c6e6bfcf0fc6ff082
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <6c32496964da0dc230cea763a0e934b2e02dabd5
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <d6a597450e686d4c6388bd3cdcb17224b4dae7f0
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <e2b2f0e2e34d71ae6c2a1114fd3c525930e84bc7
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <e7e3e90d671078455a3a08189f89d85b3da2de9e
- Affected versionversion=03e404af26dc2ea0d278d7a342de0aab394793ce <eeaa345e128515135ccb864c04482180c08e3259
- Affected versionversion=3.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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