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CVE-2025-21884 (GCVE-0-2025-21884)

Vulnerability from cvelistv5 – Published: 2025-03-27 14:57 – Updated: 2026-08-05 11:55
VLAI
Title
net: better track kernel sockets lifetime
Summary
In the Linux kernel, the following vulnerability has been resolved: net: better track kernel sockets lifetime While kernel sockets are dismantled during pernet_operations->exit(), their freeing can be delayed by any tx packets still held in qdisc or device queues, due to skb_set_owner_w() prior calls. This then trigger the following warning from ref_tracker_dir_exit() [1] To fix this, make sure that kernel sockets own a reference on net->passive. Add sk_net_refcnt_upgrade() helper, used whenever a kernel socket is converted to a refcounted one. [1] [ 136.263918][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at [ 136.263918][ T35] sk_alloc+0x2b3/0x370 [ 136.263918][ T35] inet6_create+0x6ce/0x10f0 [ 136.263918][ T35] __sock_create+0x4c0/0xa30 [ 136.263918][ T35] inet_ctl_sock_create+0xc2/0x250 [ 136.263918][ T35] igmp6_net_init+0x39/0x390 [ 136.263918][ T35] ops_init+0x31e/0x590 [ 136.263918][ T35] setup_net+0x287/0x9e0 [ 136.263918][ T35] copy_net_ns+0x33f/0x570 [ 136.263918][ T35] create_new_namespaces+0x425/0x7b0 [ 136.263918][ T35] unshare_nsproxy_namespaces+0x124/0x180 [ 136.263918][ T35] ksys_unshare+0x57d/0xa70 [ 136.263918][ T35] __x64_sys_unshare+0x38/0x40 [ 136.263918][ T35] do_syscall_64+0xf3/0x230 [ 136.263918][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 136.263918][ T35] [ 136.343488][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at [ 136.343488][ T35] sk_alloc+0x2b3/0x370 [ 136.343488][ T35] inet6_create+0x6ce/0x10f0 [ 136.343488][ T35] __sock_create+0x4c0/0xa30 [ 136.343488][ T35] inet_ctl_sock_create+0xc2/0x250 [ 136.343488][ T35] ndisc_net_init+0xa7/0x2b0 [ 136.343488][ T35] ops_init+0x31e/0x590 [ 136.343488][ T35] setup_net+0x287/0x9e0 [ 136.343488][ T35] copy_net_ns+0x33f/0x570 [ 136.343488][ T35] create_new_namespaces+0x425/0x7b0 [ 136.343488][ T35] unshare_nsproxy_namespaces+0x124/0x180 [ 136.343488][ T35] ksys_unshare+0x57d/0xa70 [ 136.343488][ T35] __x64_sys_unshare+0x38/0x40 [ 136.343488][ T35] do_syscall_64+0xf3/0x230 [ 136.343488][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 0cafd77dcd032d1687efaba5598cf07bce85997f , < 2668e038800b946d269f96ec1b258c01930a242c (git)
Affected: 0cafd77dcd032d1687efaba5598cf07bce85997f , < 4ceb0bd4ffd009821b585ce6a8033b12b59fb5fb (git)
Affected: 0cafd77dcd032d1687efaba5598cf07bce85997f , < c31a732fac46b00b95b78fcc9c37cb48dd6f2e0c (git)
Affected: 0cafd77dcd032d1687efaba5598cf07bce85997f , < 5c70eb5c593d64d93b178905da215a9fd288a4b5 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.2
Unaffected: 0 , < 6.2 (semver)
Unaffected: 6.6.103 , ≤ 6.6.* (semver)
Unaffected: 6.12.43 , ≤ 6.12.* (semver)
Unaffected: 6.13.6 , ≤ 6.13.* (semver)
Unaffected: 6.14 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/sock.h",
            "net/core/sock.c",
            "net/mptcp/subflow.c",
            "net/netlink/af_netlink.c",
            "net/rds/tcp.c",
            "net/smc/af_smc.c",
            "net/sunrpc/svcsock.c",
            "net/sunrpc/xprtsock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2668e038800b946d269f96ec1b258c01930a242c",
              "status": "affected",
              "version": "0cafd77dcd032d1687efaba5598cf07bce85997f",
              "versionType": "git"
            },
            {
              "lessThan": "4ceb0bd4ffd009821b585ce6a8033b12b59fb5fb",
              "status": "affected",
              "version": "0cafd77dcd032d1687efaba5598cf07bce85997f",
              "versionType": "git"
            },
            {
              "lessThan": "c31a732fac46b00b95b78fcc9c37cb48dd6f2e0c",
              "status": "affected",
              "version": "0cafd77dcd032d1687efaba5598cf07bce85997f",
              "versionType": "git"
            },
            {
              "lessThan": "5c70eb5c593d64d93b178905da215a9fd288a4b5",
              "status": "affected",
              "version": "0cafd77dcd032d1687efaba5598cf07bce85997f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/sock.h",
            "net/core/sock.c",
            "net/mptcp/subflow.c",
            "net/netlink/af_netlink.c",
            "net/rds/tcp.c",
            "net/smc/af_smc.c",
            "net/sunrpc/svcsock.c",
            "net/sunrpc/xprtsock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.43",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.6",
              "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": "6.6.103",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.43",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13.6",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: better track kernel sockets lifetime\n\nWhile kernel sockets are dismantled during pernet_operations-\u003eexit(),\ntheir freeing can be delayed by any tx packets still held in qdisc\nor device queues, due to skb_set_owner_w() prior calls.\n\nThis then trigger the following warning from ref_tracker_dir_exit() [1]\n\nTo fix this, make sure that kernel sockets own a reference on net-\u003epassive.\n\nAdd sk_net_refcnt_upgrade() helper, used whenever a kernel socket\nis converted to a refcounted one.\n\n[1]\n\n[  136.263918][   T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at\n[  136.263918][   T35]      sk_alloc+0x2b3/0x370\n[  136.263918][   T35]      inet6_create+0x6ce/0x10f0\n[  136.263918][   T35]      __sock_create+0x4c0/0xa30\n[  136.263918][   T35]      inet_ctl_sock_create+0xc2/0x250\n[  136.263918][   T35]      igmp6_net_init+0x39/0x390\n[  136.263918][   T35]      ops_init+0x31e/0x590\n[  136.263918][   T35]      setup_net+0x287/0x9e0\n[  136.263918][   T35]      copy_net_ns+0x33f/0x570\n[  136.263918][   T35]      create_new_namespaces+0x425/0x7b0\n[  136.263918][   T35]      unshare_nsproxy_namespaces+0x124/0x180\n[  136.263918][   T35]      ksys_unshare+0x57d/0xa70\n[  136.263918][   T35]      __x64_sys_unshare+0x38/0x40\n[  136.263918][   T35]      do_syscall_64+0xf3/0x230\n[  136.263918][   T35]      entry_SYSCALL_64_after_hwframe+0x77/0x7f\n[  136.263918][   T35]\n[  136.343488][   T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at\n[  136.343488][   T35]      sk_alloc+0x2b3/0x370\n[  136.343488][   T35]      inet6_create+0x6ce/0x10f0\n[  136.343488][   T35]      __sock_create+0x4c0/0xa30\n[  136.343488][   T35]      inet_ctl_sock_create+0xc2/0x250\n[  136.343488][   T35]      ndisc_net_init+0xa7/0x2b0\n[  136.343488][   T35]      ops_init+0x31e/0x590\n[  136.343488][   T35]      setup_net+0x287/0x9e0\n[  136.343488][   T35]      copy_net_ns+0x33f/0x570\n[  136.343488][   T35]      create_new_namespaces+0x425/0x7b0\n[  136.343488][   T35]      unshare_nsproxy_namespaces+0x124/0x180\n[  136.343488][   T35]      ksys_unshare+0x57d/0xa70\n[  136.343488][   T35]      __x64_sys_unshare+0x38/0x40\n[  136.343488][   T35]      do_syscall_64+0xf3/0x230\n[  136.343488][   T35]      entry_SYSCALL_64_after_hwframe+0x77/0x7f"
        }
      ],
      "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 bug is triggered entirely through local syscalls \u2014 `unshare(CLONE_NEWUSER|CLONE_NEWNET)` to create the netns, netlink/rtnetlink to add a device and a delaying qdisc, then namespace exit to run `cleanup_net()`; the syzbot traces show the path rooted at `__x64_sys_unshare`. No remote peer input is required or sufficient to reach it.\nAC:L - The attacker controls both halves of the window: they configure the device/qdisc that holds the kernel socket\u0027s TX skb (e.g. netem delay) and they choose exactly when to destroy the namespace, so the socket reliably outlives `net_passive_dec()`; the syzkaller reproducer hit it repeatably. Namespace churn also lets the attacker groom the freed `net_cachep` object before the deferred `__sk_destruct()` runs.\nPR:L - An unprivileged local account can create the network namespace and its per-netns kernel sockets via unprivileged user namespaces (`unshare -Urn`), which is enabled by default on mainstream distributions and Android. CAP_NET_ADMIN inside the new netns \u2014 granted automatically \u2014 is enough to add the device and qdisc needed to delay the kernel socket\u0027s skbs.\nUI:N - The attacking process performs every step itself: create the namespace, configure the delaying queue, trigger MLD/NDISC transmission, and exit. No victim action or cooperating process is needed.\nS:U - The freed `struct net`/`net-\u003egen` slab objects and the sockets that dereference them all live in the kernel\u0027s own security authority. No hypervisor, IOMMU, or sandbox boundary is crossed, so this is standard in-kernel corruption.\nC:H - The kernel socket retains a completely unreferenced `struct net *`, so after `net_passive_dec()` frees `net-\u003egen` and returns the `struct net` to `net_cachep`, subsequent `sock_net(sk)` dereferences read reallocated slab contents \u2014 the same class of defect that produced a KASAN slab-use-after-free read in the companion commit `65161fb544aa`. A use-after-free on a long-lived, attacker-groomable object yields an information-disclosure primitive.\nI:H - `__sk_destruct()` performs `__netns_tracker_free(sock_net(sk), \u0026sk-\u003ens_tracker, false)` on the dangling pointer, driving `ref_tracker_free()`\u0027s list unlink and counter updates into the freed-and-reallocated `struct net`, which is a write into attacker-groomed memory. Reallocating the freed slot with a fresh namespace also lets the stale socket operate on the wrong `struct net`, corrupting per-netns state and enabling escalation to control-flow hijack.\nA:H - Use-after-free of `struct net` and its freed `net-\u003egen` array produces oopses and panics even when not weaponized, and the pre-fix condition additionally trips `ref_tracker_dir_exit()`\u0027s WARN with `CONFIG_NET_NS_REFCNT_TRACKER=y` (fatal under `panic_on_warn`). The sequence can be repeated in a loop by an unprivileged user until the box crashes."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:55:06.894Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/2668e038800b946d269f96ec1b258c01930a242c"
        },
        {
          "url": "https://git.kernel.org/stable/c/4ceb0bd4ffd009821b585ce6a8033b12b59fb5fb"
        },
        {
          "url": "https://git.kernel.org/stable/c/c31a732fac46b00b95b78fcc9c37cb48dd6f2e0c"
        },
        {
          "url": "https://git.kernel.org/stable/c/5c70eb5c593d64d93b178905da215a9fd288a4b5"
        }
      ],
      "title": "net: better track kernel sockets lifetime",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21884",
    "datePublished": "2025-03-27T14:57:12.486Z",
    "dateReserved": "2024-12-29T08:45:45.782Z",
    "dateUpdated": "2026-08-05T11:55:06.894Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-21884",
      "date": "2026-09-16",
      "epss": "0.00211",
      "percentile": "0.11564"
    },
    "microsoft_vex": {
      "current_release_date": "2025-09-03T21:56:18.000Z",
      "cve": "CVE-2025-21884",
      "id": "msrc_CVE-2025-21884",
      "initial_release_date": "2025-03-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "net: better track kernel sockets lifetime",
      "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-21884.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-21884\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-03-27T15:15:56.313\",\"lastModified\":\"2026-07-30T06:21:54.990\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet: better track kernel sockets lifetime\\n\\nWhile kernel sockets are dismantled during pernet_operations-\u003eexit(),\\ntheir freeing can be delayed by any tx packets still held in qdisc\\nor device queues, due to skb_set_owner_w() prior calls.\\n\\nThis then trigger the following warning from ref_tracker_dir_exit() [1]\\n\\nTo fix this, make sure that kernel sockets own a reference on net-\u003epassive.\\n\\nAdd sk_net_refcnt_upgrade() helper, used whenever a kernel socket\\nis converted to a refcounted one.\\n\\n[1]\\n\\n[  136.263918][   T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at\\n[  136.263918][   T35]      sk_alloc+0x2b3/0x370\\n[  136.263918][   T35]      inet6_create+0x6ce/0x10f0\\n[  136.263918][   T35]      __sock_create+0x4c0/0xa30\\n[  136.263918][   T35]      inet_ctl_sock_create+0xc2/0x250\\n[  136.263918][   T35]      igmp6_net_init+0x39/0x390\\n[  136.263918][   T35]      ops_init+0x31e/0x590\\n[  136.263918][   T35]      setup_net+0x287/0x9e0\\n[  136.263918][   T35]      copy_net_ns+0x33f/0x570\\n[  136.263918][   T35]      create_new_namespaces+0x425/0x7b0\\n[  136.263918][   T35]      unshare_nsproxy_namespaces+0x124/0x180\\n[  136.263918][   T35]      ksys_unshare+0x57d/0xa70\\n[  136.263918][   T35]      __x64_sys_unshare+0x38/0x40\\n[  136.263918][   T35]      do_syscall_64+0xf3/0x230\\n[  136.263918][   T35]      entry_SYSCALL_64_after_hwframe+0x77/0x7f\\n[  136.263918][   T35]\\n[  136.343488][   T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at\\n[  136.343488][   T35]      sk_alloc+0x2b3/0x370\\n[  136.343488][   T35]      inet6_create+0x6ce/0x10f0\\n[  136.343488][   T35]      __sock_create+0x4c0/0xa30\\n[  136.343488][   T35]      inet_ctl_sock_create+0xc2/0x250\\n[  136.343488][   T35]      ndisc_net_init+0xa7/0x2b0\\n[  136.343488][   T35]      ops_init+0x31e/0x590\\n[  136.343488][   T35]      setup_net+0x287/0x9e0\\n[  136.343488][   T35]      copy_net_ns+0x33f/0x570\\n[  136.343488][   T35]      create_new_namespaces+0x425/0x7b0\\n[  136.343488][   T35]      unshare_nsproxy_namespaces+0x124/0x180\\n[  136.343488][   T35]      ksys_unshare+0x57d/0xa70\\n[  136.343488][   T35]      __x64_sys_unshare+0x38/0x40\\n[  136.343488][   T35]      do_syscall_64+0xf3/0x230\\n[  136.343488][   T35]      entry_SYSCALL_64_after_hwframe+0x77/0x7f\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: mejorar el seguimiento del ciclo de vida de los sockets del kernel. Mientras los sockets del kernel se desmantelan durante pernet_operations-\u0026gt;exit(), su liberaci\u00f3n puede verse retrasada por cualquier paquete de transmisi\u00f3n que a\u00fan se encuentre en la qdisc o en las colas de dispositivos, debido a llamadas previas a skb_set_owner_w(). Esto genera la siguiente advertencia de ref_tracker_dir_exit() [1]. Para solucionar esto, aseg\u00farese de que los sockets del kernel posean una referencia en net-\u0026gt;passive. Agregue el asistente sk_net_refcnt_upgrade(), que se utiliza siempre que un socket del kernel se convierte a uno con recuento de referencia.  [1] [ 136.263918][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at [ 136.263918][ T35] sk_alloc+0x2b3/0x370 [ 136.263918][ T35] inet6_create+0x6ce/0x10f0 [ 136.263918][ T35] __sock_create+0x4c0/0xa30 [ 136.263918][ T35] inet_ctl_sock_create+0xc2/0x250 [ 136.263918][ T35] igmp6_net_init+0x39/0x390 [ 136.263918][ T35] ops_init+0x31e/0x590 [ 136.263918][ T35] setup_net+0x287/0x9e0 [ 136.263918][ T35] copy_net_ns+0x33f/0x570 [ 136.263918][ T35] create_new_namespaces+0x425/0x7b0 [ 136.263918][ T35] unshare_nsproxy_namespaces+0x124/0x180 [ 136.263918][ T35] ksys_unshare+0x57d/0xa70 [ 136.263918][ T35] __x64_sys_unshare+0x38/0x40 [ 136.263918][ T35] do_syscall_64+0xf3/0x230 [ 136.263918][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 136.263918][ T35] [ 136.343488][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at [ 136.343488][ T35] sk_alloc+0x2b3/0x370 [ 136.343488][ T35] inet6_create+0x6ce/0x10f0 [ 136.343488][ T35] __sock_create+0x4c0/0xa30 [ 136.343488][ T35] inet_ctl_sock_create+0xc2/0x250 [ 136.343488][ T35] ndisc_net_init+0xa7/0x2b0 [ 136.343488][ T35] ops_init+0x31e/0x590 [ 136.343488][ T35] setup_net+0x287/0x9e0 [ 136.343488][ T35] copy_net_ns+0x33f/0x570 [ 136.343488][ T35] create_new_namespaces+0x425/0x7b0 [ 136.343488][ T35] unshare_nsproxy_namespaces+0x124/0x180 [ 136.343488][ T35] ksys_unshare+0x57d/0xa70 [ 136.343488][ T35] __x64_sys_unshare+0x38/0x40 [ 136.343488][ T35] do_syscall_64+0xf3/0x230 [ 136.343488][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"include/net/sock.h\",\"net/core/sock.c\",\"net/mptcp/subflow.c\",\"net/netlink/af_netlink.c\",\"net/rds/tcp.c\",\"net/smc/af_smc.c\",\"net/sunrpc/svcsock.c\",\"net/sunrpc/xprtsock.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"0cafd77dcd032d1687efaba5598cf07bce85997f\",\"lessThan\":\"2668e038800b946d269f96ec1b258c01930a242c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0cafd77dcd032d1687efaba5598cf07bce85997f\",\"lessThan\":\"4ceb0bd4ffd009821b585ce6a8033b12b59fb5fb\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0cafd77dcd032d1687efaba5598cf07bce85997f\",\"lessThan\":\"c31a732fac46b00b95b78fcc9c37cb48dd6f2e0c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0cafd77dcd032d1687efaba5598cf07bce85997f\",\"lessThan\":\"5c70eb5c593d64d93b178905da215a9fd288a4b5\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"include/net/sock.h\",\"net/core/sock.c\",\"net/mptcp/subflow.c\",\"net/netlink/af_netlink.c\",\"net/rds/tcp.c\",\"net/smc/af_smc.c\",\"net/sunrpc/svcsock.c\",\"net/sunrpc/xprtsock.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.2\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.2\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.103\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.43\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.13.6\",\"lessThanOrEqual\":\"6.13.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.14\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.6.103\",\"matchCriteriaId\":\"F2293654-7169-49B5-8D0D-EE51EF8B8E48\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.7\",\"versionEndExcluding\":\"6.12.43\",\"matchCriteriaId\":\"472C5F87-2BF3-4FAB-9B21-DA7513977363\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.13.6\",\"matchCriteriaId\":\"64F12D9B-71C2-4CD7-A288-0D5EF1709620\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"186716B6-2B66-4BD0-852E-D48E71C0C85F\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"0D3E781C-403A-498F-9DA9-ECEE50F41E75\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"66619FB8-0AAF-4166-B2CF-67B24143261D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*\",\"matchCriteriaId\":\"D3D6550E-6679-4560-902D-AF52DCFE905B\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2668e038800b946d269f96ec1b258c01930a242c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/4ceb0bd4ffd009821b585ce6a8033b12b59fb5fb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5c70eb5c593d64d93b178905da215a9fd288a4b5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/c31a732fac46b00b95b78fcc9c37cb48dd6f2e0c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-09-13T07:55:28+00:00",
      "cve": "CVE-2025-21884",
      "id": "CVE-2025-21884",
      "initial_release_date": "2025-03-27T00:00:00+00:00",
      "product_status:known_affected": "226",
      "product_status:known_not_affected": "48",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net: better track kernel sockets lifetime",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-21884.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-30T02:04:25Z",
      "cve": "CVE-2025-21884",
      "id": "CVE-2025-21884",
      "initial_release_date": "2025-03-28T03:00:46Z",
      "product_status:known_affected": "504",
      "product_status:known_not_affected": "317",
      "product_status:recommended": "384",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-21884",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-21884.json",
      "version": "47"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


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.