{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-56755",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2024-56755"
  ],
  "published": "2024-12-29T11:31:32Z",
  "summary": "netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING\n\nIn fscache_create_volume(), there is a missing memory barrier between the\nbit-clearing operation and the wake-up operation. This may cause a\nsituation where, after a wake-up, the bit-clearing operation hasn't been\ndetected yet, leading to an indefinite wait. The triggering process is as\nfollows:\n\n  [cookie1]                [cookie2]                  [volume_work]\nfscache_perform_lookup\n  fscache_create_volume\n                        fscache_perform_lookup\n                          fscache_create_volume\n\t\t\t                        fscache_create_volume_work\n                                                  cachefiles_acquire_volume\n                                                  clear_and_wake_up_bit\n    test_and_set_bit\n                            test_and_set_bit\n                              goto maybe_wait\n      goto no_wait\n\nIn the above process, cookie1 and cookie2 has the same volume. When cookie1\nenters the -no_wait- process, it will clear the bit and wake up the waiting\nprocess. If a barrier is missing, it may cause cookie2 to remain in the\n-wait- process indefinitely.\n\nIn commit 3288666c7256 (\"fscache: Use clear_and_wake_up_bit() in\nfscache_create_volume_work()\"), barriers were added to similar operations\nin fscache_create_volume_work(), but fscache_create_volume() was missed.\n\nBy combining the clear and wake operations into clear_and_wake_up_bit() to\nfix this issue.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "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"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.120",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-56755"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ddab02607eed9e415dc62fde421d4329e5345315"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/539fabba965e119b98066fc6ba5257b5eaf4eda2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8beb682cc9a0798a280bbb95e3e41617237090b2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8cc1df3113cb71a0df2c46dd5b102c9e11c8a8c6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/22f9400a6f3560629478e0a64247b8fcc811a24d"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}