{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 5.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-21850",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-10-01T19:26:16.776927Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-835",
                "description": "CWE-835 Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-01T19:26:38.884Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/target/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "cc0607594f6813342b27c752c6fb6f6eb9980cb5",
              "status": "affected",
              "version": "74d16965d7ac378d28ebd833ae6d6a097186a4ec",
              "versionType": "git"
            },
            {
              "lessThan": "4082326807072b71496501b6a0c55ffe8d5092a5",
              "status": "affected",
              "version": "74d16965d7ac378d28ebd833ae6d6a097186a4ec",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/target/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.14",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13.5",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: Fix crash when a namespace is disabled\n\nThe namespace percpu counter protects pending I/O, and we can\nonly safely diable the namespace once the counter drop to zero.\nOtherwise we end up with a crash when running blktests/nvme/058\n(eg for loop transport):\n\n[ 2352.930426] [  T53909] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN PTI\n[ 2352.930431] [  T53909] KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]\n[ 2352.930434] [  T53909] CPU: 3 UID: 0 PID: 53909 Comm: kworker/u16:5 Tainted: G        W          6.13.0-rc6 #232\n[ 2352.930438] [  T53909] Tainted: [W]=WARN\n[ 2352.930440] [  T53909] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014\n[ 2352.930443] [  T53909] Workqueue: nvmet-wq nvme_loop_execute_work [nvme_loop]\n[ 2352.930449] [  T53909] RIP: 0010:blkcg_set_ioprio+0x44/0x180\n\nas the queue is already torn down when calling submit_bio();\n\nSo we need to init the percpu counter in nvmet_ns_enable(), and\nwait for it to drop to zero in nvmet_ns_disable() to avoid having\nI/O pending after the namespace has been disabled."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The buggy code is in nvmet core, shared by nvmet-tcp (TCP/4420) and nvmet-rdma, and the in-flight request that holds the stale namespace reference is created and timed by a remote NVMe-oF initiator \u2014 `nvmet_req_init()` takes the ref on the command-capsule PDU and the target waits for the host\u0027s H2C data PDUs before executing. The remote peer therefore both holds the reference and picks the moment of the stale dereference.\nAC:L - The attacker can park a write command so the namespace percpu-ref is held indefinitely and then deliver the data PDU at will, so no race must be \"won\" and no memory-layout condition applies; on a loaded target there is always outstanding I/O anyway. In orchestrated NVMe-oF deployments the attacker also drives the disable side through ordinary volume detach, making both halves attacker-controlled.\nPR:N - nvmet performs no cryptographic authentication by default \u2014 admission is a plaintext host-NQN string compare (`nvmet_host_allowed()`) or `allow_any_host=1`, both trivially satisfied by an unauthenticated peer. Issuing normal read/write commands on a connection the attacker establishes requires no privilege on the target host.\nUI:N - In the realistic orchestrated/multi-tenant deployment the attacker triggers the namespace disable itself via a control-plane volume detach while holding stalled I/O, so no other user participates. Namespace disable is also routine automated reconfiguration rather than a discrete victim action.\nS:U - The corruption and its consequences are confined to the target host\u0027s kernel; no VM, IOMMU, or sandbox authority boundary is crossed.\nC:H - This is a use-after-free of `struct file`, the bvec mempool, and PR `pc_ref` slab objects, all reachable from a request whose contents the attacker controls; reclaiming those allocations with attacker-chosen data yields kernel memory disclosure via read/compare responses. Per kernel guidance, UAF is scored High for confidentiality.\nI:H - The file-backed path performs an indirect call through `req-\u003ens-\u003efile-\u003ef_op-\u003ewrite_iter` on a freed file, a direct control-flow-hijack primitive, and the PR path performs a `percpu_ref_put()` write into kfree\u0027d memory. Both are exploitable write/execute primitives after heap grooming.\nA:H - The bug reproduces as an immediate kernel oops \u2014 a general protection fault in `blkcg_set_ioprio()` from `submit_bio()` on a torn-down request queue, as recorded in the fix commit. A remote initiator can trigger this deterministically, panicking the storage target."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:54:53.966Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cc0607594f6813342b27c752c6fb6f6eb9980cb5"
        },
        {
          "url": "https://git.kernel.org/stable/c/4082326807072b71496501b6a0c55ffe8d5092a5"
        }
      ],
      "title": "nvmet: Fix crash when a namespace is disabled",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21850",
    "datePublished": "2025-03-12T09:42:05.761Z",
    "dateReserved": "2024-12-29T08:45:45.779Z",
    "dateUpdated": "2026-08-05T11:54:53.966Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}