Vulnerability-Lookup

CNVD-2026-20417

Vulnerability from cnvd - Published: 2026-05-18

Title

Linux kernel io_uring rsrc越界读取漏洞

Description

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在越界读取漏洞。该漏洞源于io_uring rsrc中零长度固定缓冲区导入时bvec跳过逻辑越界读取，攻击者可利用该漏洞导致越界内存访问。

Severity

中

Patch Name

Linux kernel io_uring rsrc越界读取漏洞的补丁

Patch Description

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在越界读取漏洞。该漏洞源于io_uring rsrc中零长度固定缓冲区导入时bvec跳过逻辑越界读取，攻击者可利用该漏洞导致越界内存访问。目前，供应商发布了安全公告及相关补丁信息，修复了此漏洞。

Formal description

厂商已发布了漏洞修复程序，请及时关注更新： https://www.kernel.org/category/releases.html

Reference

https://nvd.nist.gov/vuln/detail/CVE-2026-43006

Impacted products

Name
Linux Linux kernel

Show details on source website

JSON

To clipboard

{
  "cves": {
    "cve": {
      "cveNumber": "CVE-2026-43006",
      "cveUrl": "https://nvd.nist.gov/vuln/detail/CVE-2026-43006"
    }
  },
  "description": "Linux kernel\u662f\u7f8e\u56fdLinux\u57fa\u91d1\u4f1a\u7684\u5f00\u6e90\u64cd\u4f5c\u7cfb\u7edfLinux\u6240\u4f7f\u7528\u7684\u5185\u6838\u3002\n\nLinux kernel\u5b58\u5728\u8d8a\u754c\u8bfb\u53d6\u6f0f\u6d1e\u3002\u8be5\u6f0f\u6d1e\u6e90\u4e8eio_uring rsrc\u4e2d\u96f6\u957f\u5ea6\u56fa\u5b9a\u7f13\u51b2\u533a\u5bfc\u5165\u65f6bvec\u8df3\u8fc7\u903b\u8f91\u8d8a\u754c\u8bfb\u53d6\uff0c\u653b\u51fb\u8005\u53ef\u5229\u7528\u8be5\u6f0f\u6d1e\u5bfc\u81f4\u8d8a\u754c\u5185\u5b58\u8bbf\u95ee\u3002",
  "formalWay": "\u5382\u5546\u5df2\u53d1\u5e03\u4e86\u6f0f\u6d1e\u4fee\u590d\u7a0b\u5e8f\uff0c\u8bf7\u53ca\u65f6\u5173\u6ce8\u66f4\u65b0\uff1a\r\nhttps://www.kernel.org/category/releases.html",
  "isEvent": "\u901a\u7528\u8f6f\u786c\u4ef6\u6f0f\u6d1e",
  "number": "CNVD-2026-20417",
  "openTime": "2026-05-18",
  "patchDescription": "Linux kernel\u662f\u7f8e\u56fdLinux\u57fa\u91d1\u4f1a\u7684\u5f00\u6e90\u64cd\u4f5c\u7cfb\u7edfLinux\u6240\u4f7f\u7528\u7684\u5185\u6838\u3002\r\n\r\nLinux kernel\u5b58\u5728\u8d8a\u754c\u8bfb\u53d6\u6f0f\u6d1e\u3002\u8be5\u6f0f\u6d1e\u6e90\u4e8eio_uring rsrc\u4e2d\u96f6\u957f\u5ea6\u56fa\u5b9a\u7f13\u51b2\u533a\u5bfc\u5165\u65f6bvec\u8df3\u8fc7\u903b\u8f91\u8d8a\u754c\u8bfb\u53d6\uff0c\u653b\u51fb\u8005\u53ef\u5229\u7528\u8be5\u6f0f\u6d1e\u5bfc\u81f4\u8d8a\u754c\u5185\u5b58\u8bbf\u95ee\u3002\u76ee\u524d\uff0c\u4f9b\u5e94\u5546\u53d1\u5e03\u4e86\u5b89\u5168\u516c\u544a\u53ca\u76f8\u5173\u8865\u4e01\u4fe1\u606f\uff0c\u4fee\u590d\u4e86\u6b64\u6f0f\u6d1e\u3002",
  "patchName": "Linux kernel io_uring rsrc\u8d8a\u754c\u8bfb\u53d6\u6f0f\u6d1e\u7684\u8865\u4e01",
  "products": {
    "product": "Linux Linux kernel"
  },
  "referenceLink": "https://nvd.nist.gov/vuln/detail/CVE-2026-43006",
  "serverity": "\u4e2d",
  "submitTime": "2026-05-11",
  "title": "Linux kernel io_uring rsrc\u8d8a\u754c\u8bfb\u53d6\u6f0f\u6d1e"
}

CVE-2026-43006 (GCVE-0-2026-43006)

Vulnerability from cvelistv5 – Published: 2026-05-01 14:15 – Updated: 2026-08-05 12:25

Title

io_uring/rsrc: reject zero-length fixed buffer import

Summary

In the Linux kernel, the following vulnerability has been resolved: io_uring/rsrc: reject zero-length fixed buffer import validate_fixed_range() admits buf_addr at the exact end of the registered region when len is zero, because the check uses strict greater-than (buf_end > imu->ubuf + imu->len). io_import_fixed() then computes offset == imu->len, which causes the bvec skip logic to advance past the last bio_vec entry and read bv_offset from out-of-bounds slab memory. Return early from io_import_fixed() when len is zero. A zero-length import has no data to transfer and should not walk the bvec array at all. BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0 Read of size 4 at addr ffff888002bcc254 by task poc/103 Call Trace: io_import_reg_buf+0x697/0x7f0 io_write_fixed+0xd9/0x250 __io_issue_sqe+0xad/0x710 io_issue_sqe+0x7d/0x1100 io_submit_sqes+0x86a/0x23c0 __do_sys_io_uring_enter+0xa98/0x1590 Allocated by task 103: The buggy address is located 12 bytes to the right of allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)

Severity

7.1 (High)


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

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/040a1e7e0e2f01851…
https://git.kernel.org/stable/c/40170fc1a79c1b2e6…
https://git.kernel.org/stable/c/111a12b422a8cfa93…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8622b20f23ed165f48b8ca61503a107d17f8d585 , < 040a1e7e0e2f01851fec1dd2d96906f8636a9f75 (git) Affected: 8622b20f23ed165f48b8ca61503a107d17f8d585 , < 40170fc1a79c1b2e68f09ae6aac687b7305ae6f4 (git) Affected: 8622b20f23ed165f48b8ca61503a107d17f8d585 , < 111a12b422a8cfa93deabaef26fec48237163214 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.22 , ≤ 6.18.* (semver) Unaffected: 6.19.12 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/rsrc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "040a1e7e0e2f01851fec1dd2d96906f8636a9f75",
              "status": "affected",
              "version": "8622b20f23ed165f48b8ca61503a107d17f8d585",
              "versionType": "git"
            },
            {
              "lessThan": "40170fc1a79c1b2e68f09ae6aac687b7305ae6f4",
              "status": "affected",
              "version": "8622b20f23ed165f48b8ca61503a107d17f8d585",
              "versionType": "git"
            },
            {
              "lessThan": "111a12b422a8cfa93deabaef26fec48237163214",
              "status": "affected",
              "version": "8622b20f23ed165f48b8ca61503a107d17f8d585",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "io_uring/rsrc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.22",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.22",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.12",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/rsrc: reject zero-length fixed buffer import\n\nvalidate_fixed_range() admits buf_addr at the exact end of the\nregistered region when len is zero, because the check uses strict\ngreater-than (buf_end \u003e imu-\u003eubuf + imu-\u003elen).  io_import_fixed()\nthen computes offset == imu-\u003elen, which causes the bvec skip logic\nto advance past the last bio_vec entry and read bv_offset from\nout-of-bounds slab memory.\n\nReturn early from io_import_fixed() when len is zero.  A zero-length\nimport has no data to transfer and should not walk the bvec array\nat all.\n\n  BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0\n  Read of size 4 at addr ffff888002bcc254 by task poc/103\n  Call Trace:\n   io_import_reg_buf+0x697/0x7f0\n   io_write_fixed+0xd9/0x250\n   __io_issue_sqe+0xad/0x710\n   io_issue_sqe+0x7d/0x1100\n   io_submit_sqes+0x86a/0x23c0\n   __do_sys_io_uring_enter+0xa98/0x1590\n  Allocated by task 103:\n  The buggy address is located 12 bytes to the right of\n   allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable path is reached through local io_uring syscalls: create a ring, register a fixed buffer, then submit READ_FIXED or WRITE_FIXED. It is not reachable by remote packets or adjacent/physical input.\nAC:L - The trigger is deterministic: use len zero with buf_addr exactly at the end of a registered fixed buffer. No race or attacker-uncontrolled heap state is required to reach the out-of-bounds read.\nPR:L - An unprivileged local user can use io_uring when the upstream sysctl allows it, and buffer registration only requires ordinary user memory within resource limits. No real root or init-namespace capability is required.\nUI:N - After obtaining local execution, the attacker directly invokes io_uring_setup, io_uring_register, and io_uring_enter. No victim action is needed.\nS:U - The vulnerability is in the kernel servicing the attacker\u0027s local process and does not cross a separate security authority such as a VM host boundary. Standard local kernel compromise or crash remains Scope Unchanged.\nC:H - The bug performs an attacker-triggered out-of-bounds read from adjacent kernel slab memory while constructing the fixed-buffer bio_vec iterator. Under conservative kernel scoring, this is treated as high confidentiality impact because kernel heap data is read outside the valid object.\nI:N - The demonstrated primitive is an out-of-bounds read of bio_vec metadata, not an out-of-bounds write or use-after-free. I did not find a defensible direct data modification or control-flow overwrite primitive from this zero-length import.\nA:H - The reported path produces a KASAN slab-out-of-bounds BUG in io_import_reg_buf, and the same local trigger can be submitted repeatedly. Kernel oops/panic potential is High availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:25:13.184Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/040a1e7e0e2f01851fec1dd2d96906f8636a9f75"
        },
        {
          "url": "https://git.kernel.org/stable/c/40170fc1a79c1b2e68f09ae6aac687b7305ae6f4"
        },
        {
          "url": "https://git.kernel.org/stable/c/111a12b422a8cfa93deabaef26fec48237163214"
        }
      ],
      "title": "io_uring/rsrc: reject zero-length fixed buffer import",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43006",
    "datePublished": "2026-05-01T14:15:14.176Z",
    "dateReserved": "2026-05-01T14:12:55.974Z",
    "dateUpdated": "2026-08-05T12:25:13.184Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.