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vdpa_sim_blk: reject out-of-range sector starts

Type: advisorySource: Official CVE List1 source record

In 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.

Announced Group revision 1
Original source ↗

CVE-2026-97991

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-97991

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "2ff2a8d063fdfa1e1479fb1fe2e3356a2ce89018",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "36ef4d8527f71648f00347f6ba759f0b7e5e0977",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "000c6300776ceaf6b715780113f4275b1be4195b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "14acb0d44b7d90a077beb7b92b444b90bafda9d9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "a8a1413a2cfdbedc896249f461d6d92efbbfe21f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "d6dac17e20fd2abd0eb8c09d69fccf7426e12bcf",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "7d189f617f83f780915b737896a696ff605bd19f",
        "lessThan": "0a8693f00c408d85f086ad85d29e7030bf1e2055",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/vdpa/vdpa_sim/vdpa_sim_blk.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.13"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.13",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.15.222",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.189",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.111",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.53",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.7",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/vdpa/vdpa_sim/vdpa_sim_blk.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-97991

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#38122 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement

Revision history

  1. CVE-2026-97991 · Revision 1Source updated