FKIE_CVE-2026-31774

Vulnerability from fkie_nvd - Published: 2026-05-01 15:16 - Updated: 2026-10-19 20:17
Severity
7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs() sqe->len is __u32 but gets stored into sr->len which is int. When userspace passes sqe->len values exceeding INT_MAX (e.g. 0xFFFFFFFF), sr->len overflows to a negative value. This negative value propagates through the bundle recv/send path: 1. io_recv(): sel.val = sr->len (ssize_t gets -1) 2. io_recv_buf_select(): arg.max_len = sel->val (size_t gets 0xFFFFFFFFFFFFFFFF) 3. io_ring_buffers_peek(): buf->len is not clamped because max_len is astronomically large 4. iov[].iov_len = 0xFFFFFFFF flows into io_bundle_nbufs() 5. io_bundle_nbufs(): min_t(int, 0xFFFFFFFF, ret) yields -1, causing ret to increase instead of decrease, creating an infinite loop that reads past the allocated iov[] array This results in a slab-out-of-bounds read in io_bundle_nbufs() from the kmalloc-64 slab, as nbufs increments past the allocated iovec entries. BUG: KASAN: slab-out-of-bounds in io_bundle_nbufs+0x128/0x160 Read of size 8 at addr ffff888100ae05c8 by task exp/145 Call Trace: io_bundle_nbufs+0x128/0x160 io_recv_finish+0x117/0xe20 io_recv+0x2db/0x1160 Fix this by rejecting negative sr->len values early in both io_sendmsg_prep() and io_recvmsg_prep(). Since sqe->len is __u32, any value > INT_MAX indicates overflow and is not a valid length.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1b655cd311344117d3052f6552cb20d9901c9d7cPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/90ced24c500ad4e129e9e34b7e56fd7849e350b6Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b948f9d5d3057b01188e36664e7c7604d1c8ecb5Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c314b405dcc4d8b9041124f928f81715d6328becPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/net.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "90ced24c500ad4e129e9e34b7e56fd7849e350b6",
              "status": "affected",
              "version": "a05d1f625c7aa681d8816bc0f10089289ad07aad",
              "versionType": "git"
            },
            {
              "lessThan": "c314b405dcc4d8b9041124f928f81715d6328bec",
              "status": "affected",
              "version": "a05d1f625c7aa681d8816bc0f10089289ad07aad",
              "versionType": "git"
            },
            {
              "lessThan": "1b655cd311344117d3052f6552cb20d9901c9d7c",
              "status": "affected",
              "version": "a05d1f625c7aa681d8816bc0f10089289ad07aad",
              "versionType": "git"
            },
            {
              "lessThan": "b948f9d5d3057b01188e36664e7c7604d1c8ecb5",
              "status": "affected",
              "version": "a05d1f625c7aa681d8816bc0f10089289ad07aad",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "io_uring/net.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.81",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
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              "versionEndExcluding": "6.12.81",
              "versionStartIncluding": "6.10",
              "vulnerable": true
            },
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              "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6",
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          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()\n\nsqe-\u003elen is __u32 but gets stored into sr-\u003elen which is int. When\nuserspace passes sqe-\u003elen values exceeding INT_MAX (e.g. 0xFFFFFFFF),\nsr-\u003elen overflows to a negative value. This negative value propagates\nthrough the bundle recv/send path:\n\n  1. io_recv(): sel.val = sr-\u003elen (ssize_t gets -1)\n  2. io_recv_buf_select(): arg.max_len = sel-\u003eval (size_t gets\n     0xFFFFFFFFFFFFFFFF)\n  3. io_ring_buffers_peek(): buf-\u003elen is not clamped because max_len\n     is astronomically large\n  4. iov[].iov_len = 0xFFFFFFFF flows into io_bundle_nbufs()\n  5. io_bundle_nbufs(): min_t(int, 0xFFFFFFFF, ret) yields -1,\n     causing ret to increase instead of decrease, creating an\n     infinite loop that reads past the allocated iov[] array\n\nThis results in a slab-out-of-bounds read in io_bundle_nbufs() from\nthe kmalloc-64 slab, as nbufs increments past the allocated iovec\nentries.\n\n  BUG: KASAN: slab-out-of-bounds in io_bundle_nbufs+0x128/0x160\n  Read of size 8 at addr ffff888100ae05c8 by task exp/145\n  Call Trace:\n   io_bundle_nbufs+0x128/0x160\n   io_recv_finish+0x117/0xe20\n   io_recv+0x2db/0x1160\n\nFix this by rejecting negative sr-\u003elen values early in both\nio_sendmsg_prep() and io_recvmsg_prep(). Since sqe-\u003elen is __u32,\nany value \u003e INT_MAX indicates overflow and is not a valid length."
    }
  ],
  "id": "CVE-2026-31774",
  "lastModified": "2026-10-19T20:17:59.037",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-31774",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T15:13:11.625324Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-01T15:16:40.720",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/1b655cd311344117d3052f6552cb20d9901c9d7c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "url": "https://git.kernel.org/stable/c/90ced24c500ad4e129e9e34b7e56fd7849e350b6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/b948f9d5d3057b01188e36664e7c7604d1c8ecb5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/c314b405dcc4d8b9041124f928f81715d6328bec"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-190"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}



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