ext4: fix slab-use-after-free in ext4_split_extent_at()

{
  "id": "3d838350d45328a0a8120aa8d5683c97d007b891e57491926aec4adedf44fcb7",
  "url": "https://osv.dev/vulnerability/CVE-2024-49884",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ext4: fix slab-use-after-free in ext4_split_extent_at()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ext4: fix slab-use-after-free in ext4_split_extent_at() We hit the following use-after-free: ================================================================== BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0 Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40 CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724 Call Trace: kasan_report+0x93/0xc0 ext4_split_extent_at+0xba8/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_blocks+0xe20/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] Allocated by task 40: __kmalloc_noprof+0x1ac/0x480 ext4_find_extent+0xf3b/0x1e70 ext4_ext_map_blocks+0x188/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] Freed by task 40: kfree+0xf1/0x2b0 ext4_find_extent+0xa71/0x1e70 ext4_ext_insert_extent+0xa22/0x3260 ext4_split_extent_at+0x3ef/0xcc0 ext4_split_extent.isra.0+0x18f/0x500 ext4_split_convert_extents+0x275/0x750 ext4_ext_handle_unwritten_extents+0x73e/0x1580 ext4_ext_map_blocks+0xe20/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ================================================================== The flow of issue triggering is as follows: ext4_split_extent_at path = *ppath ext4_ext_insert_extent(ppath) ext4_ext_create_new_leaf(ppath) ext4_find_extent(orig_path) path = ",
    "evidence": "osv:CVE-2024-49884",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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            "value": "4.19.323",
            "evidence": "/affected/1/ranges"
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          {
            "value": "5.4.290",
            "evidence": "/affected/1/ranges"
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          {
            "value": "5.10.227",
            "evidence": "/affected/1/ranges"
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          {
            "value": "5.15.168",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.113",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.55",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.10.14",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.11.3",
            "evidence": "/affected/1/ranges"
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        "affected_versions": []
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    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2024-49884",
      "aliases": [
        "CVE-2024-49884"
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      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
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                  "fixed": "cafcc1bd62934547c76abf46c6d0d54f135006fe"
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                  "fixed": "a5401d4c3e2a3d25643c567d26e6de327774a2c9"
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                {
                  "fixed": "8fe117790b37c84c651e2bad9efc0e7fda73c0e3"
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                {
                  "fixed": "5d949ea75bb529ea6342e83465938a3b0ac51238"
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                  "fixed": "915ac3630488af0ca194dc63b86d99802b4f6e18"
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                {
                  "fixed": "c26ab35702f8cd0cdc78f96aa5856bfb77be798f"
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          "database_specific": {
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            "ecosystem": "Linux"
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            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-49884.json"
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      ],
      "modified": "2026-10-28T02:30:32.821024915Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-355557.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
        "https://git.kernel.org/stable/c/393a46f60ea4f249dc9d496d4eb2d542f5e11ade",
        "https://git.kernel.org/stable/c/448100a29395b0c8b4c42967155849fe0fbe808f",
        "https://git.kernel.org/stable/c/5d949ea75bb529ea6342e83465938a3b0ac51238",
        "https://git.kernel.org/stable/c/8fe117790b37c84c651e2bad9efc0e7fda73c0e3",
        "https://git.kernel.org/stable/c/915ac3630488af0ca194dc63b86d99802b4f6e18",
        "https://git.kernel.org/stable/c/a5401d4c3e2a3d25643c567d26e6de327774a2c9",
        "https://git.kernel.org/stable/c/c26ab35702f8cd0cdc78f96aa5856bfb77be798f",
        "https://git.kernel.org/stable/c/cafcc1bd62934547c76abf46c6d0d54f135006fe",
        "https://git.kernel.org/stable/c/e52f933598b781d291b9297e39c463536da0e185",
        "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html",
        "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49884.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-49884",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/49xxx/CVE-2024-49884.json"
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    "related_cves": [
      {
        "value": "CVE-2024-49884",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499814,
  "published_at": "2024-10-21T18:01:21.517+00:00"
}