{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-42102",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2024-42102"
  ],
  "published": "2024-07-30T07:47:52Z",
  "summary": "Revert \"mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again\"",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again\"\n\nPatch series \"mm: Avoid possible overflows in dirty throttling\".\n\nDirty throttling logic assumes dirty limits in page units fit into\n32-bits.  This patch series makes sure this is true (see patch 2/2 for\nmore details).\n\n\nThis patch (of 2):\n\nThis reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78.\n\nThe commit is broken in several ways.  Firstly, the removed (u64) cast\nfrom the multiplication will introduce a multiplication overflow on 32-bit\narchs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the\ndefault settings with 4GB of RAM will trigger this).  Secondly, the\ndiv64_u64() is unnecessarily expensive on 32-bit archs.  We have\ndiv64_ul() in case we want to be safe & cheap.  Thirdly, if dirty\nthresholds are larger than 1<<32 pages, then dirty balancing is going to\nblow up in many other spectacular ways anyway so trying to fix one\npossible overflow is just moot.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.6.20-1+rpt1",
        "1:6.6.28-1+rpt1",
        "1:6.6.31-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "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-v6",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v7",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v7l",
            "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-v6",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v7",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v7l",
            "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-v6",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v7",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v7l",
            "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"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.6.20-1+rpt1": {
            "linux_commit": "6f16847710cc0502450788b9f12f0a14d3429668",
            "upstream_version": "6.6.20",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.39"
          },
          "1:6.6.28-1+rpt1": {
            "linux_commit": "0c341f47adc3578cd5f817aa20ee2b7f9ae6b23e",
            "upstream_version": "6.6.28",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.39"
          },
          "1:6.6.31-1+rpt1": {
            "linux_commit": "c1432b4bae5b6582f4d32ba381459f33c34d1424",
            "upstream_version": "6.6.31",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.39"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-42102"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/253f9ea7e8e53a5176bd80ceb174907b10724c1a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/23a28f5f3f6ca1e4184bd0e9631cd0944cf1c807"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/145faa3d03688cbb7bbaaecbd84c01539852942c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2820005edae13b140f2d54267d1bd6bb23915f59"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/cbbe17a324437c0ff99881a3ee453da45b228a00"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f6620df12cb6bdcad671d269debbb23573502f9d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/000099d71648504fb9c7a4616f92c2b70c3e44ec"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/30139c702048f1097342a31302cbd3d478f50c63"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-24T06:48:58Z"
  }
}