Service interruption via detached NAPI queue leak
Published Oct 7, 2025 · Updated Oct 7, 2025
Memory leakage in the TUN driver in Linux 3.8 through 6.4-rc2 allows local users to exhaust memory via a detached NAPI queue. In tun_get_user, write() can append an skb to tfile->sk.sk_write_queue after ioctl(IFF_DETACH_QUEUE) purges and detaches the queue because detached is checked outside the queue lock. Exploitation requires access to /dev/net/tun and a TUN device configured with NAPI and multiqueue; repeated races leak socket and skb allocations until service availability is impaired.
Summary
What happened
Memory leakage in the TUN driver in Linux 3.8 through 6.4-rc2 allows local users to exhaust memory via a detached NAPI queue. In tun_get_user, write() can append an skb to tfile->sk.sk_write_queue after ioctl(IFF_DETACH_QUEUE) purges and detaches the queue because detached is checked outside the queue lock. Exploitation requires access to /dev/net/tun and a TUN device configured with NAPI and multiqueue; repeated races leak socket and skb allocations until service availability is impaired.
The record
- CVE
- CVE-2023-53685
- Published
- Oct 7, 2025
- Updated
- Oct 7, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-401, T1499.004
- Attack vector
- local
- Privileges
- Unavailable
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=3.8
- Affected versionversion=cde8b15f1aabe327038ee4e0e11dd6b798572f69 <0d20210a190f76db9ec35ee4e0fc77e6c7a148f5
- Affected versionversion=cde8b15f1aabe327038ee4e0e11dd6b798572f69 <82b2bc279467c875ec36f8ef820f00997c2a4e8e
- Affected versionversion=cde8b15f1aabe327038ee4e0e11dd6b798572f69 <9cae243b9ae25adfe468cd47ceca591f6725b79c
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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