{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-53136",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2024-53136"
  ],
  "published": "2024-12-04T14:29:17Z",
  "summary": "mm: revert \"mm: shmem: fix data-race in shmem_getattr()\"",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: revert \"mm: shmem: fix data-race in shmem_getattr()\"\n\nRevert d949d1d14fa2 (\"mm: shmem: fix data-race in shmem_getattr()\") as\nsuggested by Chuck [1].  It is causing deadlocks when accessing tmpfs over\nNFS.\n\nAs Hugh commented, \"added just to silence a syzbot sanitizer splat: added\nwhere there has never been any practical problem\".",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.6.62-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "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-v6",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v7",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v7l",
            "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"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.6.62-1+rpt1": {
            "linux_commit": "dd2394360860d15146c96635796a75b05bb32b61",
            "upstream_version": "6.6.62",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.63"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-53136"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/36b537e8f302f670c7cf35d88a3a294443e32d52"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a3c65022d89d5baa2cea8e87a6de983ea305f14c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/57cc8d253099d1b8627f0fb487ee011d9158ccc9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d3f9d88c2c03b2646ace336236adca19f7697bd3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5874c1150e77296565ad6e495ef41fbf87570d14"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/64e67e8694252c1bf01b802ee911be3fee62c36b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/901dc2ad7c3789fa87dc3956f6697c5d62d5cf7e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d1aa0c04294e29883d65eac6c2f72fe95cc7c049"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.5,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - The deadlock is triggered by nfsd processing NFS RPCs from a remote client over TCP/2049 against a tmpfs export \u2014 `nfsd_setattr()`/`nfsd_create()`/`nfsd_unlink()`/`nfsd_rename()` hold `i_rwsem` for write and then call `vfs_getattr()` on the same inode. A remote NFS client issuing a single CREATE or SETATTR hangs the server.\nAC:L - This is a deterministic recursive rwsem acquisition (`down_write` then `down_read` on the same lock by the same task), not a race \u2014 every metadata-modifying NFS operation on a tmpfs export deadlocks 100% of the time on the first attempt.\nPR:N - NFSv3/NFSv4 with AUTH_SYS performs no cryptographic authentication \u2014 a client permitted by the export simply asserts a UID, so no credentials on the server are required; a world-writable or anon-squashed tmpfs export lets an entirely unauthenticated remote peer reach `fh_fill_pre_attrs()` under the held inode lock.\nUI:N - The attacker sends the NFS request directly; no action by a local user or administrator is needed at exploit time, only the pre-existing tmpfs export configuration.\nS:U - The deadlocked task, the held `i_rwsem`, and all resulting hangs are within the kernel's own security authority; no boundary between security scopes is crossed.\nC:N - The bug is a lock-ordering/recursion deadlock with no out-of-bounds access, no freed-memory reuse, and no data returned to the attacker \u2014 nothing is disclosed.\nI:N - No memory corruption or unauthorized modification occurs; the operation simply never completes, so no data is written incorrectly.\nA:H - The nfsd thread blocks unkillably in `TASK_UNINTERRUPTIBLE` while holding the inode's `i_rwsem` forever, wedging every further access to that inode from both NFS clients and local processes and exhausting nfsd threads \u2014 a permanent, unrecoverable denial of service requiring a reboot."
    }
  }
}