{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-21756",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2025-21756"
  ],
  "published": "2025-02-27T02:18:18Z",
  "summary": "vsock: Keep the binding until socket destruction",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: Keep the binding until socket destruction\n\nPreserve sockets bindings; this includes both resulting from an explicit\nbind() and those implicitly bound through autobind during connect().\n\nPrevents socket unbinding during a transport reassignment, which fixes a\nuse-after-free:\n\n    1. vsock_create() (refcnt=1) calls vsock_insert_unbound() (refcnt=2)\n    2. transport->release() calls vsock_remove_bound() without checking if\n       sk was bound and moved to bound list (refcnt=1)\n    3. vsock_bind() assumes sk is in unbound list and before\n       __vsock_insert_bound(vsock_bound_sockets()) calls\n       __vsock_remove_bound() which does:\n           list_del_init(&vsk->bound_table); // nop\n           sock_put(&vsk->sk);               // refcnt=0\n\nBUG: KASAN: slab-use-after-free in __vsock_bind+0x62e/0x730\nRead of size 4 at addr ffff88816b46a74c by task a.out/2057\n dump_stack_lvl+0x68/0x90\n print_report+0x174/0x4f6\n kasan_report+0xb9/0x190\n __vsock_bind+0x62e/0x730\n vsock_bind+0x97/0xe0\n __sys_bind+0x154/0x1f0\n __x64_sys_bind+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nAllocated by task 2057:\n kasan_save_stack+0x1e/0x40\n kasan_save_track+0x10/0x30\n __kasan_slab_alloc+0x85/0x90\n kmem_cache_alloc_noprof+0x131/0x450\n sk_prot_alloc+0x5b/0x220\n sk_alloc+0x2c/0x870\n __vsock_create.constprop.0+0x2e/0xb60\n vsock_create+0xe4/0x420\n __sock_create+0x241/0x650\n __sys_socket+0xf2/0x1a0\n __x64_sys_socket+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nFreed by task 2057:\n kasan_save_stack+0x1e/0x40\n kasan_save_track+0x10/0x30\n kasan_save_free_info+0x37/0x60\n __kasan_slab_free+0x4b/0x70\n kmem_cache_free+0x1a1/0x590\n __sk_destruct+0x388/0x5a0\n __vsock_bind+0x5e1/0x730\n vsock_bind+0x97/0xe0\n __sys_bind+0x154/0x1f0\n __x64_sys_bind+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 7 PID: 2057 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150\nRIP: 0010:refcount_warn_saturate+0xce/0x150\n __vsock_bind+0x66d/0x730\n vsock_bind+0x97/0xe0\n __sys_bind+0x154/0x1f0\n __x64_sys_bind+0x6e/0xb0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nrefcount_t: underflow; use-after-free.\nWARNING: CPU: 7 PID: 2057 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150\nRIP: 0010:refcount_warn_saturate+0xee/0x150\n vsock_remove_bound+0x187/0x1e0\n __vsock_release+0x383/0x4a0\n vsock_release+0x90/0x120\n __sock_release+0xa3/0x250\n sock_close+0x14/0x20\n __fput+0x359/0xa80\n task_work_run+0x107/0x1d0\n do_exit+0x847/0x2560\n do_group_exit+0xb8/0x250\n __x64_sys_exit_group+0x3a/0x50\n x64_sys_call+0xfec/0x14f0\n do_syscall_64+0x93/0x1b0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.21-1+rpt1",
        "1:6.1.47-1+rpt2",
        "1:6.1.47-1+rpt4",
        "1:6.1.54-1+rpt2",
        "1:6.1.58-1+rpt2",
        "1:6.1.63-1+rpt1",
        "1:6.1.73-1+rpt1",
        "1:6.6.20-1+rpt1",
        "1:6.6.28-1+rpt1",
        "1:6.6.31-1+rpt1",
        "1:6.6.47-1+rpt1",
        "1:6.6.51-1+rpt1",
        "1:6.6.51-1+rpt2",
        "1:6.6.51-1+rpt3",
        "1:6.6.62-1+rpt1",
        "1:6.6.74-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v8",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi2-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-2712",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-v8",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-2712",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-v8",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-2712",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-v8",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-2712",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-v8",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-2712",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v8",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-2712",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v8",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-2712",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v8",
            "binary_version": "1:6.6.31-1+rpt1"
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            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v8",
            "binary_version": "1:6.6.47-1+rpt1"
          },
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            "binary_name": "linux-image-6.6.51+rpt-rpi-2712",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v8",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-2712",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v8",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-2712",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v8",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-2712",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v8",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.74+rpt-rpi-2712",
            "binary_version": "1:6.6.74-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.74+rpt-rpi-v8",
            "binary_version": "1:6.6.74-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.21-1+rpt1": {
            "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed",
            "upstream_version": "6.1.21",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.131"
          },
          "1:6.1.47-1+rpt2": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.131"
          },
          "1:6.1.47-1+rpt4": {
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            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.131",
            "compiled_filter": false
          },
          "1:6.1.54-1+rpt2": {
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            "upstream_version": "6.1.54",
            "assessment": "commit ancestry (strak rule)",
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          },
          "1:6.1.58-1+rpt2": {
            "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18",
            "upstream_version": "6.1.58",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.131"
          },
          "1:6.1.63-1+rpt1": {
            "linux_commit": null,
            "upstream_version": "6.1.63",
            "assessment": "upstream version (no usable Linux commit)",
            "upstream_fixed": "6.1.131"
          },
          "1:6.1.73-1+rpt1": {
            "linux_commit": null,
            "upstream_version": "6.1.73",
            "assessment": "upstream version (no usable Linux commit)",
            "upstream_fixed": "6.1.131"
          },
          "1:6.6.20-1+rpt1": {
            "linux_commit": "6f16847710cc0502450788b9f12f0a14d3429668",
            "upstream_version": "6.6.20",
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            "assessment": "commit ancestry (strak rule)",
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            "upstream_version": "6.6.51",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.79"
          },
          "1:6.6.51-1+rpt2": {
            "linux_commit": "82a50e430ef1d6eb37d78e25aa572c1f6ea56160",
            "upstream_version": "6.6.51",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.79"
          },
          "1:6.6.51-1+rpt3": {
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            "upstream_version": "6.6.51",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.79"
          },
          "1:6.6.62-1+rpt1": {
            "linux_commit": "dd2394360860d15146c96635796a75b05bb32b61",
            "upstream_version": "6.6.62",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.79"
          },
          "1:6.6.74-1+rpt1": {
            "linux_commit": "a18d9ced4965462cb7b3b4252ada440395105308",
            "upstream_version": "6.6.74",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.79"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-21756"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e7754d564579a5db9c5c9f74228df5d6dd6f1173"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e48fcb403c2d0e574c19683f09399ab4cf67809c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/42b33381e5e1f2b967dc4fb4221ddb9aaf10d197"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3f43540166128951cc1be7ab1ce6b7f05c670d8b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/645ce25aa0e67895b11d89f27bb86c9d444c40f8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b1afd40321f1c243cffbcf40ea7ca41aca87fa5e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fcdd2242c0231032fc84e1404315c245ae56322a"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z"
  }
}