Local privilege escalation via TCP-AO key use-after-free
Published May 9, 2024 · Updated Aug 5, 2026
Use-after-free in Linux 6.7 through 6.8.8 allows local users to escalate privileges through a configured TCP-AO socket. tcp_ao_connect_init schedules unmatched keys with call_rcu while traversing outside an RCU read-side critical section, so a grace period can free the current key before the iterator reads its next pointer. Any unprivileged local process can add TCP-AO keys and invoke connect; reclaiming the stale key enables kernel-memory disclosure, heap writes, privilege escalation, or a kernel panic.
Summary
What happened
Use-after-free in Linux 6.7 through 6.8.8 allows local users to escalate privileges through a configured TCP-AO socket. tcp_ao_connect_init schedules unmatched keys with call_rcu while traversing outside an RCU read-side critical section, so a grace period can free the current key before the iterator reads its next pointer. Any unprivileged local process can add TCP-AO keys and invoke connect; reclaiming the stale key enables kernel-memory disclosure, heap writes, privilege escalation, or a kernel panic.
The record
- CVE
- CVE-2024-27394
- Published
- May 9, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 9, 2024CVE 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=6.7
- Affected versionversion=7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f <80e679b352c3ce5158f3f778cfb77eb767e586fb
- Affected versionversion=7c2ffaf21bd67f73d21560995ce17eaf5fc1d37f <ca4fb6c6764b3f75b4f5aa81db1536291897ff7f
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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