System hang via IRQ-context callback lock deadlock
Published May 6, 2026 · Updated May 6, 2026
Denial of service in affected Linux Kernel releases allows local users to hang the system during transmit timestamp completion. skb_may_tx_timestamp() acquires sock::sk_callback_lock from a dedicated device IRQ handler, so a write lock already held on the same CPU deadlocks timestamp completion. Exploitation requires local low-privileged access and a driver that completes transmit timestamps in a dedicated interrupt; the resulting lockup affects availability only.
Summary
What happened
Denial of service in affected Linux Kernel releases allows local users to hang the system during transmit timestamp completion. skb_may_tx_timestamp() acquires sock::sk_callback_lock from a dedicated device IRQ handler, so a write lock already held on the same CPU deadlocks timestamp completion. Exploitation requires local low-privileged access and a driver that completes transmit timestamps in a dedicated interrupt; the resulting lockup affects availability only.
The record
- CVE
- CVE-2026-43216
- Published
- May 6, 2026
- Updated
- May 6, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-476, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 6, 2026CVE publishedPublication date reported by the CVE source.
- May 6, 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=4.0
- Affected versionversion=b245be1f4db1a0394e4b6eb66059814b46670ac3 <983512f3a87fd8dc4c94dfa6b596b6e57df5aad7
- Affected versionversion=b245be1f4db1a0394e4b6eb66059814b46670ac3 <e4c6efb3b70ff87f1df99efce2f8893717695718
- Affected versionversion=b245be1f4db1a0394e4b6eb66059814b46670ac3 <f3e4cceafad27c9363c33622732f86722846ec6f
What conditions does exploitation require?
What is affected?
Published CVSS scores
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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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