Local privilege escalation via TUN teardown use-after-free
Published Oct 21, 2024 · Updated Aug 5, 2026
Use-after-free in affected Linux kernel revisions allows local users to execute code in kernel context during TUN device teardown. In __tun_detach(), sock_put() drops the final reference to struct net before netdev_state_change() invokes notifier_call_chain() on the freed object. Opening /dev/net/tun, attaching a nonpersistent TUN interface with TUNSETIFF, and closing the descriptor requires CAP_NET_ADMIN in the user namespace; user namespaces let local users meet that gate, leading to kernel memory disclosure, arbitrary writes, code execution, or a kernel panic.
Summary
What happened
Use-after-free in affected Linux kernel revisions allows local users to execute code in kernel context during TUN device teardown. In __tun_detach(), sock_put() drops the final reference to struct net before netdev_state_change() invokes notifier_call_chain() on the freed object. Opening /dev/net/tun, attaching a nonpersistent TUN interface with TUNSETIFF, and closing the descriptor requires CAP_NET_ADMIN in the user namespace; user namespaces let local users meet that gate, leading to kernel memory disclosure, arbitrary writes, code execution, or a kernel panic.
The record
- CVE
- CVE-2022-49014
- Published
- Oct 21, 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
- Oct 21, 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=4.17
- Affected versionversion=83c1f36f9880814b24cdf6c2f91f66f61db65326 <04b995e963229501401810dab89dc73e7f12d054
- Affected versionversion=83c1f36f9880814b24cdf6c2f91f66f61db65326 <16c244bc65d1175775325ec0489a5a5c830e02c7
- Affected versionversion=83c1f36f9880814b24cdf6c2f91f66f61db65326 <1f23f1890d91812c35d32eab1b49621b6d32dc7b
- Affected versionversion=83c1f36f9880814b24cdf6c2f91f66f61db65326 <4cde8da2d814a3b7b176db81922d4ddaad7c0f0e
- Affected versionversion=83c1f36f9880814b24cdf6c2f91f66f61db65326 <5daadc86f27ea4d691e2131c04310d0418c6cd12
- Affected versionversion=83c1f36f9880814b24cdf6c2f91f66f61db65326 <5f442e1d403e0496bacb74a58e2be7f500695e6f
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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