{"cve":"CVE-2026-53062","nvd":{"published":"2026-06-24T17:17:19.030","modified":"2026-10-19T20:18:57.460","status":"Modified","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\"","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-667","CWE-362"],"references":["https://git.kernel.org/stable/c/1b2bec4a7dcf5f00b7a1cbeeec8997841d783513","https://git.kernel.org/stable/c/2b62d0611c9af14a16bddf22df2612b4f40eb5a1","https://git.kernel.org/stable/c/2d1f7b65f5deedd2e6b09fdc6ea27f8375f24b45","https://git.kernel.org/stable/c/4991b5a08751e2e82488fb93ae08849b6aea10d9","https://git.kernel.org/stable/c/93627a29d4b66d4a2def938dfb8610cc80ae454b"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-53062","score":0.00097,"percentile":0.00732,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}