Kernel stale-memory access via BPF teardown race
Published Feb 22, 2024 · Updated May 11, 2026
Use-after-free in the Linux kernel 6.2 through affected 6.7 builds allows local users to access freed memory during BPF map teardown. bpf_map_put schedules BTF destruction through RCU before deferred map freeing, so bpf_rb_root_free dereferences a value_rec pointer into the freed struct_metas_tab. The gate is local low-privileged execution plus winning a rare teardown race; KASAN demonstrated an invalid four-byte kernel-memory read.
Summary
What happened
Use-after-free in the Linux kernel 6.2 through affected 6.7 builds allows local users to access freed memory during BPF map teardown. bpf_map_put schedules BTF destruction through RCU before deferred map freeing, so bpf_rb_root_free dereferences a value_rec pointer into the freed struct_metas_tab. The gate is local low-privileged execution plus winning a rare teardown race; KASAN demonstrated an invalid four-byte kernel-memory read.
The record
- CVE
- CVE-2023-52446
- Published
- Feb 22, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 22, 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=6.2
- Affected versionversion=958cf2e273f0929c66169e0788031310e8118722 <59e5791f59dd83e8aa72a4e74217eabb6e8cfd90
- Affected versionversion=958cf2e273f0929c66169e0788031310e8118722 <d048dced8ea5eac6723ae873a40567e6f101ea42
- Affected versionversion=958cf2e273f0929c66169e0788031310e8118722 <f9ff6ef1c73cd9e1a6bb1ab3e57c5d141a536306
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Your stack
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