Local privilege escalation via BPF refcount race
Published Oct 7, 2025 · Updated Oct 7, 2025
Use-after-free in Linux kernel 6.4 through 6.4.3 allows local users with BPF-load access to execute code in kernel context. After a failed rbtree insertion drops a non-owning node, bpf_refcount_acquire_impl increments a zero reference count and can return a dangling owning reference. Loading and racing attacker-authored BPF programs requires BPF program-load privileges; successful reuse exposes kernel memory to reads, writes, and system crashes.
Summary
What happened
Use-after-free in Linux kernel 6.4 through 6.4.3 allows local users with BPF-load access to execute code in kernel context. After a failed rbtree insertion drops a non-owning node, bpf_refcount_acquire_impl increments a zero reference count and can return a dangling owning reference. Loading and racing attacker-authored BPF programs requires BPF program-load privileges; successful reuse exposes kernel memory to reads, writes, and system crashes.
The record
- CVE
- CVE-2023-53645
- Published
- Oct 7, 2025
- Updated
- Oct 7, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 7, 2025CVE publishedPublication date reported by the CVE source.
- Oct 7, 2025Record 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=6.4
- Affected versionversion=d2dcc67df910dd85253a701b6a5b747f955d28f5 <7793fc3babe9fea908e57f7c187ea819f9fd7e95
- Affected versionversion=d2dcc67df910dd85253a701b6a5b747f955d28f5 <d906d1b940b9dbf0a3e821d6b32a51c369273d91
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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