In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix zerocopy completion for multi-skb sends When a large message… (CVE-2026-53365)
A vulnerability in the Linux kernel's vsock/virtio zerocopy implementation was fixed. The issue involved improper handling of zerocopy completion for large messages fragmented into multiple skbs, leading to pinned user pages leaking without completion notification. This could cause resource exhaustion due to unreleased pinned pages. The fix ensures proper allocation and reference counting of zerocopy user arguments for all skbs in a send loop, preventing leaks.
AI Analysis
Technical Summary
The Linux kernel vsock/virtio zerocopy implementation had a flaw where, during multi-skb sends of large messages, the zerocopy user argument (uarg) was only allocated for the last skb. Non-final skbs carried pinned user pages without completion tracking, so if the send loop exited early, pinned pages leaked without notification to userspace. The fix adopts a TCP-like approach by allocating the uarg before the send loop and attaching it to every skb with proper reference counting, ensuring completion notifications occur only after all skbs are freed. On failure with no data sent, the uarg is cleanly aborted. This vulnerability relates to resource leaks (CWE-401) and was discovered during code review of a prior fix.
Potential Impact
This vulnerability can lead to leaking pinned user pages in the kernel, causing resource exhaustion and potential denial of service (availability impact). There is no confidentiality or integrity impact reported. No known exploits in the wild have been documented.
Mitigation Recommendations
A fix for this vulnerability has been implemented in the Linux kernel. Since no explicit patch links or vendor advisory are provided, check the official Linux kernel repositories or vendor advisories for the fixed versions and apply updates accordingly. Patch status is not yet confirmed from the provided data — verify with vendor sources for current remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix zerocopy completion for multi-skb sends When a large message… (CVE-2026-53365)
Description
A vulnerability in the Linux kernel's vsock/virtio zerocopy implementation was fixed. The issue involved improper handling of zerocopy completion for large messages fragmented into multiple skbs, leading to pinned user pages leaking without completion notification. This could cause resource exhaustion due to unreleased pinned pages. The fix ensures proper allocation and reference counting of zerocopy user arguments for all skbs in a send loop, preventing leaks.
CVSS v3.1
Score 5.5medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vsock/virtio zerocopy implementation had a flaw where, during multi-skb sends of large messages, the zerocopy user argument (uarg) was only allocated for the last skb. Non-final skbs carried pinned user pages without completion tracking, so if the send loop exited early, pinned pages leaked without notification to userspace. The fix adopts a TCP-like approach by allocating the uarg before the send loop and attaching it to every skb with proper reference counting, ensuring completion notifications occur only after all skbs are freed. On failure with no data sent, the uarg is cleanly aborted. This vulnerability relates to resource leaks (CWE-401) and was discovered during code review of a prior fix.
Potential Impact
This vulnerability can lead to leaking pinned user pages in the kernel, causing resource exhaustion and potential denial of service (availability impact). There is no confidentiality or integrity impact reported. No known exploits in the wild have been documented.
Mitigation Recommendations
A fix for this vulnerability has been implemented in the Linux kernel. Since no explicit patch links or vendor advisory are provided, check the official Linux kernel repositories or vendor advisories for the fixed versions and apply updates accordingly. Patch status is not yet confirmed from the provided data — verify with vendor sources for current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-9p63-4jq7-2c9w
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-53365"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a55ffab68715ace432fa185
Added to database: 07/14/2026, 09:21:47 UTC
Last enriched: 07/23/2026, 00:14:57 UTC
Last updated: 07/31/2026, 19:24:47 UTC
Views: 13
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