dm cache policy smq: fix missing locks in invalidating cache blocks_CVE-2026-53062

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm cache policy smq: fix missing locks in invalidating cache blocks\n\nIn passthrough mode, the policy invalidate_mapping operation is called\nsimultaneously from multiple workers, thus it should be protected by a\nlock. Otherwise, we might end up with data races on the allocated blocks\ncounter, or even use-after-free issues with internal data structures\nwhen doing concurrent writes.\n\nNote that the existing FIXME in smq_invalidate_mapping() doesn't affect\npassthrough mode since migration tasks don't exist there, but would need\nattention if supporting fast device shrinking via suspend/resume without\ntarget reloading.\n\nReproduce steps:\n\n1. Create a cache device consisting of 1024 cache entries\n\ndmsetup create cmeta --table \"0 8192 linear /dev/sdc 0\"\ndmsetup create cdata --table \"0 131072 linear /dev/sdc 8192\"\ndmsetup create corig --table \"0 262144 linear /dev/sdc 262144\"\ndd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct\ndmsetup create cache --table \"0 262144 cache /dev/mapper/cmeta \\\n/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0\"\n\n2. Populate the cache, and record the number of cached blocks\n\nfio --name=populate --filename=/dev/mapper/cache --rw=randwrite --bs=4k \\\n--size=64m --direct=1\nnr_cached=$(dmsetup status cache | awk '{split($7, a, \"/\"); print a[1]}')\n\n3. Reload the cache into passthrough mode\n\ndmsetup suspend cache\ndmsetup reload cache --table \"0 262144 cache /dev/mapper/cmeta \\\n/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 passthrough smq 0\"\ndmsetup resume cache\n\n4. Write to the passthrough cache. By setting multiple jobs with I/O\n   size equal to the cache block size, cache blocks are invalidated\n   concurrently from different workers.\n\nfio --filename=/dev/mapper/cache --name=test --rw=randwrite --bs=64k \\\n--direct=1 --numjobs=2 --randrepeat=0 --size=64m\n\n5. Check if demoted matches cached block count. These numbers should\n   match but may differ due to the data race.\n\nnr_demoted=$(dmsetup status cache | awk '{print $12}')\necho \"$nr_cached, $nr_demoted\"",
    "published": "2026-06-24T16:30:06.189Z",
    "modified": "2026-06-28T06:38:50.387Z",
    "type": "cve",
    "title": "dm cache policy smq: fix missing locks in invalidating cache blocks",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/4991b5a08751e2e82488fb93ae08849b6aea10d9\nhttps://git.kernel.org/stable/c/1b2bec4a7dcf5f00b7a1cbeeec8997841d783513\nhttps://git.kernel.org/stable/c/9a5fdfb9e57ec3a8ad2b8fce5e5ffa42d53b130e\nhttps://git.kernel.org/stable/c/ac5ee99443891bdb161f5539606a66a1b5e72542\nhttps://git.kernel.org/stable/c/93627a29d4b66d4a2def938dfb8610cc80ae454b\nhttps://git.kernel.org/stable/c/c348ae47d8e65f06429fa41adce9ad986b696766\nhttps://git.kernel.org/stable/c/2b62d0611c9af14a16bddf22df2612b4f40eb5a1\nhttps://git.kernel.org/stable/c/2d1f7b65f5deedd2e6b09fdc6ea27f8375f24b45",
    "id": "CVE-2026-53062",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux b29d4986d0da1a27cd35917cdb433672f5c95d7f\nLinux Linux 4.12",
    "sourceHref": "",
    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
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        "baseScore": 0,
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        "cvssV3": {
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    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "b29d4986d0da1a27cd35917cdb433672f5c95d7f",
    "vendor": "Linux",
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}