Bug 2460712 (CVE-2026-31468)

Summary: CVE-2026-31468 kernel: vfio/pci: Fix double free in dma-buf feature
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's vfio/pci dma-buf feature. An issue in the error handling of the `vfio_pci_core_feature_dma_buf()` function can lead to a double free of allocated memory. This can occur under specific conditions, such as file descriptor exhaustion, potentially causing system instability or a denial of service (DoS).
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Description OSIDB Bzimport 2026-04-22 15:06:56 UTC 
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.
Comment 1 Keith Grant 2026-04-22 18:06:09 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042253-CVE-2026-31468-13b8@gregkh/T