Vulnerability-Lookup

GHSA-22QM-W4F2-G533

Vulnerability from github – Published: 2026-09-16 12:30 – Updated: 2026-09-16 15:31

Details

In the Linux kernel, the following vulnerability has been resolved:

scsi: bsg: Fix TOCTOU in io_uring passthrough command setup

scsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap'd SQE. Userspace can change a field after we check it and before we use it. request_len is the sharp case: it can grow past sizeof(scmd->cmnd) after the bound check and overflow scmd->cmnd in copy_from_user().

READ_ONCE() the SQE fields we check or use into locals before use.

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-90009"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T11:17:13Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: bsg: Fix TOCTOU in io_uring passthrough command setup\n\nscsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap\u0027d SQE.\nUserspace can change a field after we check it and before we use it.\nrequest_len is the sharp case: it can grow past sizeof(scmd-\u003ecmnd) after\nthe bound check and overflow scmd-\u003ecmnd in copy_from_user().\n\nREAD_ONCE() the SQE fields we check or use into locals before use.",
  "id": "GHSA-22qm-w4f2-g533",
  "modified": "2026-09-16T15:31:06Z",
  "published": "2026-09-16T12:30:45Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90009"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4b3c5965fca99f62d31c963294bd5b23cc488e97"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f033530105aa73d82c121d54b57f358e4865d2f4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-90009 (GCVE-0-2026-90009)

Vulnerability from cvelistv5 – Published: 2026-09-16 10:33 – Updated: 2026-09-16 14:41

Title

scsi: bsg: Fix TOCTOU in io_uring passthrough command setup

Summary

In the Linux kernel, the following vulnerability has been resolved: scsi: bsg: Fix TOCTOU in io_uring passthrough command setup scsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap'd SQE. Userspace can change a field after we check it and before we use it. request_len is the sharp case: it can grow past sizeof(scmd->cmnd) after the bound check and overflow scmd->cmnd in copy_from_user(). READ_ONCE() the SQE fields we check or use into locals before use.

Severity

7.8 (High)


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

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/f033530105aa73d82…
https://git.kernel.org/stable/c/4b3c5965fca99f62d…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 7b6d3255e7f8c6df2d21504c47808e3ce84649ac , < f033530105aa73d82c121d54b57f358e4865d2f4 (git) Affected: 7b6d3255e7f8c6df2d21504c47808e3ce84649ac , < 4b3c5965fca99f62d31c963294bd5b23cc488e97 (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.5 , ≤ 7.2.* (semver) Unaffected: 7.3-rc2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/scsi/scsi_bsg.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f033530105aa73d82c121d54b57f358e4865d2f4",
              "status": "affected",
              "version": "7b6d3255e7f8c6df2d21504c47808e3ce84649ac",
              "versionType": "git"
            },
            {
              "lessThan": "4b3c5965fca99f62d31c963294bd5b23cc488e97",
              "status": "affected",
              "version": "7b6d3255e7f8c6df2d21504c47808e3ce84649ac",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/scsi/scsi_bsg.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.5",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc2",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: bsg: Fix TOCTOU in io_uring passthrough command setup\n\nscsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap\u0027d SQE.\nUserspace can change a field after we check it and before we use it.\nrequest_len is the sharp case: it can grow past sizeof(scmd-\u003ecmnd) after\nthe bound check and overflow scmd-\u003ecmnd in copy_from_user().\n\nREAD_ONCE() the SQE fields we check or use into locals before use."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - scsi_bsg_uring_cmd() is reached only via a local io_uring IORING_OP_URING_CMD on a SCSI BSG device node (/dev/bsg/\u003ch:c:i:l\u003e); io_uring and BSG are local syscall/device paths, not a network protocol handler.\nAC:L - The attacker owns both sides of the TOCTOU: one thread submits the uring_cmd while another rewrites request_len in the shared mmap\u0027d SQE. The inline issue path never copies the SQE first, and scsi_alloc_request() sits between the bound check and copy_from_user, making the race attacker-driven and retryable.\nPR:L - bsg_open() has no capability check; access is only DAC on /dev/bsg/* for ordinary SCSI devices. scsi_cmd_allowed() runs after the overflow. Disk/cdrom group membership and uaccess on removable SCSI/USB devices grant this to unprivileged local users without init-namespace root.\nUI:N - The attacker opens the BSG node, creates an io_uring ring with SQE128/CQE32, and submits the racing passthrough command themselves; no victim action is required.\nS:U - The overflow corrupts the blk-mq scsi_cmnd PDU and adjacent kernel heap in the same host kernel security authority, enabling local privilege escalation rather than a VM, IOMMU, or sandbox boundary crossing.\nC:H - copy_from_user() overflows the 32-byte scmd-\u003ecmnd into scsi_cmnd pointer fields (sdb, sense_buffer, host_scribble) and adjacent heap with attacker-controlled bytes, which can be groomed into kernel memory disclosure.\nI:H - The same attacker-controlled heap overflow overwrites kernel pointers and adjacent blk-mq request objects, providing a write primitive exploitable for control-flow hijacking and privilege escalation.\nA:H - A large request_len smash or later use of corrupted scsi_cmnd pointers causes a kernel oops or panic; even a failed copy_from_user still writes through kernel memory until a fault, then frees the corrupted request."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T14:41:25.065Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f033530105aa73d82c121d54b57f358e4865d2f4"
        },
        {
          "url": "https://git.kernel.org/stable/c/4b3c5965fca99f62d31c963294bd5b23cc488e97"
        }
      ],
      "title": "scsi: bsg: Fix TOCTOU in io_uring passthrough command setup",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90009",
    "datePublished": "2026-09-16T10:33:17.446Z",
    "dateReserved": "2026-09-11T19:38:34.781Z",
    "dateUpdated": "2026-09-16T14:41:25.065Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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