{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fb2eb9ddf556f93fef45201e1f9d2b8674bcc975",
              "status": "affected",
              "version": "216c8f5ef0f209a3797292c487bdaa6991ab4b92",
              "versionType": "git"
            },
            {
              "lessThan": "f40139fde5278d81af3227444fd6e76a76b9506d",
              "status": "affected",
              "version": "216c8f5ef0f209a3797292c487bdaa6991ab4b92",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.14.*",
              "status": "unaffected",
              "version": "6.14.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14.6",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.15",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nublk: fix race between io_uring_cmd_complete_in_task and ublk_cancel_cmd\n\nublk_cancel_cmd() calls io_uring_cmd_done() to complete uring_cmd, but\nwe may have scheduled task work via io_uring_cmd_complete_in_task() for\ndispatching request, then kernel crash can be triggered.\n\nFix it by not trying to canceling the command if ublk block request is\nstarted."
        }
      ],
      "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 - The race is reached only through local interfaces \u2014 `/dev/ublk-control` and `/dev/ublkc*` io_uring passthrough commands plus block I/O to `/dev/ublkb*`. There is no remote or adjacent-network path into ublk_drv.\nAC:L - The attacker owns both sides of the race: one thread submits I/O to the ublk block device (queueing `ublk_cmd_tw_cb` task work) while another tears down the io_uring ring or issues `UBLK_CMD_STOP_DEV`, driving `ublk_cancel_cmd()`. The window can be hit repeatedly in a loop with high queue depth until it lands.\nPR:L - ublk explicitly supports `UBLK_F_UNPRIVILEGED_DEV`, where `ublk_ctrl_add_dev()` accepts non-`CAP_SYS_ADMIN` callers and all later control commands gate only on file permissions of `/dev/ublkc*`, so an ordinary local user (including inside a container) can create and drive the device. Only basic local-user access is needed, not real root.\nUI:N - The attacking process performs every step itself \u2014 creating the ublk device, issuing I/O, and triggering cancellation. No victim action or interaction is required.\nS:U - The corruption is confined to kernel heap objects (`io_kiocb`) within the same security authority; the ublk driver and io_uring both run in the kernel\u0027s own scope. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed io_uring request is dereferenced and re-completed, so an attacker who reclaims the slab object controls its contents and can have kernel data posted back through the CQE and the ublk io path. Per UAF guidance this constitutes a path to arbitrary kernel memory disclosure.\nI:H - The second `io_uring_cmd_done()` writes result fields into and relinks a freed `io_kiocb`, and the request is freed twice \u2014 a write-after-free plus double-free on a well-known io_uring slab that is a standard heap-spray target for control-flow hijack. This is high-integrity memory corruption, not a bounded write.\nA:H - The commit states plainly that \"kernel crash can be triggered,\" and the double completion corrupts io_uring\u0027s completion/task-work lists. Any unprivileged local user with a ublk device can panic the machine on demand."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:58:13.306Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/fb2eb9ddf556f93fef45201e1f9d2b8674bcc975"
        },
        {
          "url": "https://git.kernel.org/stable/c/f40139fde5278d81af3227444fd6e76a76b9506d"
        }
      ],
      "title": "ublk: fix race between io_uring_cmd_complete_in_task and ublk_cancel_cmd",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-37906",
    "datePublished": "2025-05-20T15:21:39.633Z",
    "dateReserved": "2025-04-16T04:51:23.966Z",
    "dateUpdated": "2026-08-05T11:58:13.306Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}