CVE-2026-31468
Received Received - Intake
Double Free Vulnerability in Linux vfio/pci dma-buf Feature

Publication date: 2026-04-22

Last updated on: 2026-04-27

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Fix double free in dma-buf feature The error path through vfio_pci_core_feature_dma_buf() ignores its own advice to only use dma_buf_put() after dma_buf_export(), instead falling through the entire unwind chain. In the unlikely event that we encounter file descriptor exhaustion, this can result in an unbalanced refcount on the vfio device and double free of allocated objects. Avoid this by moving the "put" directly into the error path and return the errno rather than entering the unwind chain.
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Meta Information
Published
2026-04-22
Last Modified
2026-04-27
Generated
2026-05-07
AI Q&A
2026-04-22
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's vfio/pci component, specifically related to the dma-buf feature. The issue is a double free error caused by an improper error handling path in the function vfio_pci_core_feature_dma_buf(). The function incorrectly ignores its own guideline to only call dma_buf_put() after dma_buf_export(), leading to an unbalanced reference count on the vfio device and a double free of allocated objects when file descriptor exhaustion occurs.

The fix involves moving the dma_buf_put() call directly into the error path and returning the error number immediately, preventing the function from continuing through the unwind chain and causing the double free.


How can this vulnerability impact me? :

This vulnerability can lead to a double free of allocated objects within the Linux kernel's vfio device handling. Such a double free can cause memory corruption, which may result in system instability, crashes, or potentially allow an attacker to execute arbitrary code or escalate privileges if exploited.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, you should update your Linux kernel to a version where the vfio/pci double free issue in the dma-buf feature has been fixed.

The fix involves correcting the error path in vfio_pci_core_feature_dma_buf() to avoid double freeing by properly handling dma_buf_put() calls and returning errors without entering the unwind chain.

Applying the latest kernel patches or upgrading to the latest stable kernel release that includes this fix is the recommended immediate step.


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