Bug 2516835 (CVE-2026-74312) - CVE-2026-74312 kernel: vhost/vdpa: validate virtqueue index in mmap and fault paths
Summary: CVE-2026-74312 kernel: vhost/vdpa: validate virtqueue index in mmap and fault...
Keywords:
Status: NEW
Alias: CVE-2026-74312
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:36 UTC by OSIDB Bzimport
Modified: 2026-08-20 16:29 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-08-15 06:36:00 UTC
In the Linux kernel, the following vulnerability has been resolved:

vhost/vdpa: validate virtqueue index in mmap and fault paths

vhost_vdpa_mmap() and vhost_vdpa_fault() use vma->vm_pgoff as a
virtqueue index for get_vq_notification(), but they do not validate
that the index is smaller than v->nvqs.

The ioctl path already performs both a bounds check and
array_index_nospec(), but the mmap/fault path only checks that the
index fits in u16. This allows an out-of-range queue index to reach
driver-specific get_vq_notification() callbacks.

Fix this by extracting a unified vhost_vdpa_get_vq_notification()
helper that validates the queue index against v->nvqs and applies
array_index_nospec() before calling the driver callback. Both the
mmap and fault paths use this helper, and the bounds checking is
consolidated into a single location.

From source inspection, the most defensible impact is out-of-bounds
access in the callback path, potentially leading to invalid PFN
remaps and crash/DoS.


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