vdpa_sim_blk: reject out-of-range sector starts

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-97991
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-25 11:17:27 UTC
Updated2026-10-03 11:18:22 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: vdpa_sim_blk: reject out-of-range sector starts vdpasim_blk_check_range() logs an invalid start sector but continues validating the request. The subsequent unsigned capacity subtraction can underflow and let an out-of-range buffer offset reach the data path. The invalid offset is used by three request paths. VIRTIO_BLK_T_OUT copies guest data to blk->buffer + offset through vringh_iov_pull_iotlb(), causing an out-of-bounds write in _copy_from_iter() or memcpy(). VIRTIO_BLK_T_IN copies from blk->buffer + offset to the guest through vringh_iov_push_iotlb(), causing an out-of-bounds read in _copy_to_iter(). VIRTIO_BLK_T_WRITE_ZEROES passes blk->buffer + offset to memset(), causing an out-of-bounds write. Reject starts at or beyond the capacity before the subtraction. Treat the capacity boundary as invalid because the IN and OUT paths round byte counts down to sectors for validation but later copy the original byte counts. A sub-sector request at the capacity boundary would otherwise still access past the end of the buffer. I found this bug myself, though the patch was written with AI assistance.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS: 0.001220000 probability, percentile 0.017300000 (date 2026-10-05)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.8HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
3.1CNADECLARED7.8HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f 2ff2a8d063fdfa1e1479fb1fe2e3356a2ce89018 git Not specified
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f 36ef4d8527f71648f00347f6ba759f0b7e5e0977 git Not specified
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f 000c6300776ceaf6b715780113f4275b1be4195b git Not specified
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f 14acb0d44b7d90a077beb7b92b444b90bafda9d9 git Not specified
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f a8a1413a2cfdbedc896249f461d6d92efbbfe21f git Not specified
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f d6dac17e20fd2abd0eb8c09d69fccf7426e12bcf git Not specified
CNA Linux Linux affected 7d189f617f83f780915b737896a696ff605bd19f 0a8693f00c408d85f086ad85d29e7030bf1e2055 git Not specified
CNA Linux Linux affected 5.13 Not specified
CNA Linux Linux unaffected 5.13 semver Not specified
CNA Linux Linux unaffected 5.15.222 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.189 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.158 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.111 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.53 6.18.* semver Not specified
CNA Linux Linux unaffected 7.2.7 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3-rc3 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/a8a1413a2cfdbedc896249f461d6d92efbbfe21f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/0a8693f00c408d85f086ad85d29e7030bf1e2055 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/d6dac17e20fd2abd0eb8c09d69fccf7426e12bcf 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/36ef4d8527f71648f00347f6ba759f0b7e5e0977 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/2ff2a8d063fdfa1e1479fb1fe2e3356a2ce89018 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/000c6300776ceaf6b715780113f4275b1be4195b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/14acb0d44b7d90a077beb7b92b444b90bafda9d9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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