Local resource exhaustion via premature descriptor publication
Published Sep 16, 2026 · Updated Sep 16, 2026
Resource leakage in the Linux dma-buf heap framework allows local users to retain inaccessible descriptors through failed allocation ioctls. DMA_HEAP_IOCTL_ALLOC publishes a dma-buf descriptor before copy_to_user returns it, so an EFAULT leaves the descriptor and buffer reference live but unknown to the caller. Repeated access to a dma-heap device can exhaust descriptors or retained DMA buffers, and the trigger requires local device access plus a user-memory protection change during the ioctl.
Summary
What happened
Resource leakage in the Linux dma-buf heap framework allows local users to retain inaccessible descriptors through failed allocation ioctls. DMA_HEAP_IOCTL_ALLOC publishes a dma-buf descriptor before copy_to_user returns it, so an EFAULT leaves the descriptor and buffer reference live but unknown to the caller. Repeated access to a dma-heap device can exhaust descriptors or retained DMA buffers, and the trigger requires local device access plus a user-memory protection change during the ioctl.
The record
- CVE
- CVE-2026-89996
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=5.6
- Affected versionversion=c02a81fba74fe3488ad6b08bfb5a1329005418f8 <0d4a5d218055db29b50cc07d3d73d27007c2a391
- Affected versionversion=c02a81fba74fe3488ad6b08bfb5a1329005418f8 <30d0aff2c65a277135cfd8ea28fa1ee75e0ea4e0
- Affected versionversion=c02a81fba74fe3488ad6b08bfb5a1329005418f8 <69d57dbadb27ffd5eef34fd184bab145500cdabc
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- dmabuf-heaps fd-leak-on-EFAULT regression selftestproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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