Vulnerability-Lookup

CNVD-2025-03430

Vulnerability from cnvd - Published: 2025-02-21

Title

Linux kernel mlx5e_xfrm_del_state函数拒绝服务漏洞

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存在拒绝服务漏洞，该漏洞源于mlx5e_xfrm_add_state和mlx5e_xfrm_del_state函数中对软中断（SOFTIRQ）安全锁的使用不当，攻击者可利用该漏洞导致在启用IPsec隧道模式时出现锁依赖冲突，可能引发系统崩溃。

Severity

中

Patch Name

Linux kernel mlx5e_xfrm_del_state函数拒绝服务漏洞的补丁

Patch Description

Formal description

厂商已发布了漏洞修复程序，请及时关注更新： https://git.kernel.org/stable/c/2c3688090f8a1f085230aa839cc63e4a7b977df0

Reference

https://nvd.nist.gov/vuln/detail/CVE-2025-21674

Impacted products

Name
Linux Kernel

Show details on source website

JSON

To clipboard

{
  "cves": {
    "cve": {
      "cveNumber": "CVE-2025-21674",
      "cveUrl": "https://nvd.nist.gov/vuln/detail/CVE-2025-21674"
    }
  },
  "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\u62d2\u7edd\u670d\u52a1\u6f0f\u6d1e\uff0c\u8be5\u6f0f\u6d1e\u6e90\u4e8emlx5e_xfrm_add_state\u548cmlx5e_xfrm_del_state\u51fd\u6570\u4e2d\u5bf9\u8f6f\u4e2d\u65ad\uff08SOFTIRQ\uff09\u5b89\u5168\u9501\u7684\u4f7f\u7528\u4e0d\u5f53\uff0c\u653b\u51fb\u8005\u53ef\u5229\u7528\u8be5\u6f0f\u6d1e\u5bfc\u81f4\u5728\u542f\u7528IPsec\u96a7\u9053\u6a21\u5f0f\u65f6\u51fa\u73b0\u9501\u4f9d\u8d56\u51b2\u7a81\uff0c\u53ef\u80fd\u5f15\u53d1\u7cfb\u7edf\u5d29\u6e83\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://git.kernel.org/stable/c/2c3688090f8a1f085230aa839cc63e4a7b977df0",
  "isEvent": "\u901a\u7528\u8f6f\u786c\u4ef6\u6f0f\u6d1e",
  "number": "CNVD-2025-03430",
  "openTime": "2025-02-21",
  "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\u62d2\u7edd\u670d\u52a1\u6f0f\u6d1e\uff0c\u8be5\u6f0f\u6d1e\u6e90\u4e8emlx5e_xfrm_add_state\u548cmlx5e_xfrm_del_state\u51fd\u6570\u4e2d\u5bf9\u8f6f\u4e2d\u65ad\uff08SOFTIRQ\uff09\u5b89\u5168\u9501\u7684\u4f7f\u7528\u4e0d\u5f53\uff0c\u653b\u51fb\u8005\u53ef\u5229\u7528\u8be5\u6f0f\u6d1e\u5bfc\u81f4\u5728\u542f\u7528IPsec\u96a7\u9053\u6a21\u5f0f\u65f6\u51fa\u73b0\u9501\u4f9d\u8d56\u51b2\u7a81\uff0c\u53ef\u80fd\u5f15\u53d1\u7cfb\u7edf\u5d29\u6e83\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 mlx5e_xfrm_del_state\u51fd\u6570\u62d2\u7edd\u670d\u52a1\u6f0f\u6d1e\u7684\u8865\u4e01",
  "products": {
    "product": "Linux Kernel"
  },
  "referenceLink": "https://nvd.nist.gov/vuln/detail/CVE-2025-21674",
  "serverity": "\u4e2d",
  "submitTime": "2025-02-17",
  "title": "Linux kernel mlx5e_xfrm_del_state\u51fd\u6570\u62d2\u7edd\u670d\u52a1\u6f0f\u6d1e"
}

CVE-2025-21674 (GCVE-0-2025-21674)

Vulnerability from cvelistv5 – Published: 2025-01-31 11:25 – Updated: 2026-05-11 21:04

Title

net/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel

Summary

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel Attempt to enable IPsec packet offload in tunnel mode in debug kernel generates the following kernel panic, which is happening due to two issues: 1. In SA add section, the should be _bh() variant when marking SA mode. 2. There is not needed flush_workqueue in SA delete routine. It is not needed as at this stage as it is removed from SADB and the running work will be canceled later in SA free. ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.12.0+ #4 Not tainted ----------------------------------------------------- charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire: ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core] and this task is already holding: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30 which would create a new lock dependency: (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3} but this new dependency connects a SOFTIRQ-irq-safe lock: (&x->lock){+.-.}-{3:3} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_timer_handler+0x91/0xd70 __hrtimer_run_queues+0x1dd/0xa60 hrtimer_run_softirq+0x146/0x2e0 handle_softirqs+0x266/0x860 irq_exit_rcu+0x115/0x1a0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x16/0x20 default_idle+0x13/0x20 default_idle_call+0x67/0xa0 do_idle+0x2da/0x320 cpu_startup_entry+0x50/0x60 start_secondary+0x213/0x2a0 common_startup_64+0x129/0x138 to a SOFTIRQ-irq-unsafe lock: (&xa->xa_lock#24){+.+.}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1be/0x520 _raw_spin_lock+0x2c/0x40 xa_set_mark+0x70/0x110 mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core] xfrm_dev_state_add+0x3bb/0xd70 xfrm_add_sa+0x2451/0x4a90 xfrm_user_rcv_msg+0x493/0x880 netlink_rcv_skb+0x12e/0x380 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x42f/0x740 netlink_sendmsg+0x745/0xbe0 __sock_sendmsg+0xc5/0x190 __sys_sendto+0x1fe/0x2c0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xa->xa_lock#24); local_irq_disable(); lock(&x->lock); lock(&xa->xa_lock#24); <Interrupt> lock(&x->lock); *** DEADLOCK *** 2 locks held by charon/1337: #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90 #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&x->lock){+.-.}-{3:3} ops: 29 { HARDIRQ-ON-W at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_alloc_spi+0xc0/0xe60 xfrm_alloc_userspi+0x5f6/0xbc0 xfrm_user_rcv_msg+0x493/0x880 netlink_rcv_skb+0x12e/0x380 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x42f/0x740 netlink_sendmsg+0x745/0xbe0 __sock_sendmsg+0xc5/0x190 __sys_sendto+0x1fe/0x2c0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 IN-SOFTIRQ-W at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_timer_handler+0x91/0xd70 __hrtimer_run_queues+0x1dd/0xa60 ---truncated---

Severity

5.5 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-10-01 19:52 UTC

CWE

CWE-667 - Improper Locking

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7056 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/87c4417a902151cfe…
https://git.kernel.org/stable/c/6d3d69c070d920fbb…
https://git.kernel.org/stable/c/2c3688090f8a1f085…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4c24272b4e2befca6ad1409c3c9aaa16c24b1099 , < 87c4417a902151cfe4363166245a3671a08c256c (git) Affected: 4c24272b4e2befca6ad1409c3c9aaa16c24b1099 , < 6d3d69c070d920fbb146d73dd3899a50f25d0901 (git) Affected: 4c24272b4e2befca6ad1409c3c9aaa16c24b1099 , < 2c3688090f8a1f085230aa839cc63e4a7b977df0 (git)
Linux	Linux	Affected: 6.4 Unaffected: 0 , < 6.4 (semver) Unaffected: 6.6.74 , ≤ 6.6.* (semver) Unaffected: 6.12.11 , ≤ 6.12.* (semver) Unaffected: 6.13 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "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-2025-21674",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-10-01T19:52:04.971447Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-667",
                "description": "CWE-667 Improper Locking",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-01T19:57:11.871Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "87c4417a902151cfe4363166245a3671a08c256c",
              "status": "affected",
              "version": "4c24272b4e2befca6ad1409c3c9aaa16c24b1099",
              "versionType": "git"
            },
            {
              "lessThan": "6d3d69c070d920fbb146d73dd3899a50f25d0901",
              "status": "affected",
              "version": "4c24272b4e2befca6ad1409c3c9aaa16c24b1099",
              "versionType": "git"
            },
            {
              "lessThan": "2c3688090f8a1f085230aa839cc63e4a7b977df0",
              "status": "affected",
              "version": "4c24272b4e2befca6ad1409c3c9aaa16c24b1099",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.4"
            },
            {
              "lessThan": "6.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.74",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.74",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.11",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13",
                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel\n\nAttempt to enable IPsec packet offload in tunnel mode in debug kernel\ngenerates the following kernel panic, which is happening due to two\nissues:\n1. In SA add section, the should be _bh() variant when marking SA mode.\n2. There is not needed flush_workqueue in SA delete routine. It is not\nneeded as at this stage as it is removed from SADB and the running work\nwill be canceled later in SA free.\n\n =====================================================\n WARNING: SOFTIRQ-safe -\u003e SOFTIRQ-unsafe lock order detected\n 6.12.0+ #4 Not tainted\n -----------------------------------------------------\n charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:\n ffff88810f365020 (\u0026xa-\u003exa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]\n\n and this task is already holding:\n ffff88813e0f0d48 (\u0026x-\u003elock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30\n which would create a new lock dependency:\n  (\u0026x-\u003elock){+.-.}-{3:3} -\u003e (\u0026xa-\u003exa_lock#24){+.+.}-{3:3}\n\n but this new dependency connects a SOFTIRQ-irq-safe lock:\n  (\u0026x-\u003elock){+.-.}-{3:3}\n\n ... which became SOFTIRQ-irq-safe at:\n   lock_acquire+0x1be/0x520\n   _raw_spin_lock_bh+0x34/0x40\n   xfrm_timer_handler+0x91/0xd70\n   __hrtimer_run_queues+0x1dd/0xa60\n   hrtimer_run_softirq+0x146/0x2e0\n   handle_softirqs+0x266/0x860\n   irq_exit_rcu+0x115/0x1a0\n   sysvec_apic_timer_interrupt+0x6e/0x90\n   asm_sysvec_apic_timer_interrupt+0x16/0x20\n   default_idle+0x13/0x20\n   default_idle_call+0x67/0xa0\n   do_idle+0x2da/0x320\n   cpu_startup_entry+0x50/0x60\n   start_secondary+0x213/0x2a0\n   common_startup_64+0x129/0x138\n\n to a SOFTIRQ-irq-unsafe lock:\n  (\u0026xa-\u003exa_lock#24){+.+.}-{3:3}\n\n ... which became SOFTIRQ-irq-unsafe at:\n ...\n   lock_acquire+0x1be/0x520\n   _raw_spin_lock+0x2c/0x40\n   xa_set_mark+0x70/0x110\n   mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]\n   xfrm_dev_state_add+0x3bb/0xd70\n   xfrm_add_sa+0x2451/0x4a90\n   xfrm_user_rcv_msg+0x493/0x880\n   netlink_rcv_skb+0x12e/0x380\n   xfrm_netlink_rcv+0x6d/0x90\n   netlink_unicast+0x42f/0x740\n   netlink_sendmsg+0x745/0xbe0\n   __sock_sendmsg+0xc5/0x190\n   __sys_sendto+0x1fe/0x2c0\n   __x64_sys_sendto+0xdc/0x1b0\n   do_syscall_64+0x6d/0x140\n   entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\n other info that might help us debug this:\n\n  Possible interrupt unsafe locking scenario:\n\n        CPU0                    CPU1\n        ----                    ----\n   lock(\u0026xa-\u003exa_lock#24);\n                                local_irq_disable();\n                                lock(\u0026x-\u003elock);\n                                lock(\u0026xa-\u003exa_lock#24);\n   \u003cInterrupt\u003e\n     lock(\u0026x-\u003elock);\n\n  *** DEADLOCK ***\n\n 2 locks held by charon/1337:\n  #0: ffffffff87f8f858 (\u0026net-\u003exfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90\n  #1: ffff88813e0f0d48 (\u0026x-\u003elock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30\n\n the dependencies between SOFTIRQ-irq-safe lock and the holding lock:\n -\u003e (\u0026x-\u003elock){+.-.}-{3:3} ops: 29 {\n    HARDIRQ-ON-W at:\n                     lock_acquire+0x1be/0x520\n                     _raw_spin_lock_bh+0x34/0x40\n                     xfrm_alloc_spi+0xc0/0xe60\n                     xfrm_alloc_userspi+0x5f6/0xbc0\n                     xfrm_user_rcv_msg+0x493/0x880\n                     netlink_rcv_skb+0x12e/0x380\n                     xfrm_netlink_rcv+0x6d/0x90\n                     netlink_unicast+0x42f/0x740\n                     netlink_sendmsg+0x745/0xbe0\n                     __sock_sendmsg+0xc5/0x190\n                     __sys_sendto+0x1fe/0x2c0\n                     __x64_sys_sendto+0xdc/0x1b0\n                     do_syscall_64+0x6d/0x140\n                     entry_SYSCALL_64_after_hwframe+0x4b/0x53\n    IN-SOFTIRQ-W at:\n                     lock_acquire+0x1be/0x520\n                     _raw_spin_lock_bh+0x34/0x40\n                     xfrm_timer_handler+0x91/0xd70\n                     __hrtimer_run_queues+0x1dd/0xa60\n   \n---truncated---"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:04:15.154Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/87c4417a902151cfe4363166245a3671a08c256c"
        },
        {
          "url": "https://git.kernel.org/stable/c/6d3d69c070d920fbb146d73dd3899a50f25d0901"
        },
        {
          "url": "https://git.kernel.org/stable/c/2c3688090f8a1f085230aa839cc63e4a7b977df0"
        }
      ],
      "title": "net/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21674",
    "datePublished": "2025-01-31T11:25:36.661Z",
    "dateReserved": "2024-12-29T08:45:45.736Z",
    "dateUpdated": "2026-05-11T21:04:15.154Z",
    "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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

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.

Action not permitted