{"id":"CVE-2026-53062","summary":"dm cache policy smq: fix missing locks in invalidating cache blocks","details":"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\"","modified":"2026-07-16T03:32:41.903681386Z","published":"2026-06-24T16:30:06.189Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53062.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1b2bec4a7dcf5f00b7a1cbeeec8997841d783513"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2b62d0611c9af14a16bddf22df2612b4f40eb5a1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2d1f7b65f5deedd2e6b09fdc6ea27f8375f24b45"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4991b5a08751e2e82488fb93ae08849b6aea10d9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/93627a29d4b66d4a2def938dfb8610cc80ae454b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9a5fdfb9e57ec3a8ad2b8fce5e5ffa42d53b130e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac5ee99443891bdb161f5539606a66a1b5e72542"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c348ae47d8e65f06429fa41adce9ad986b696766"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53062.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53062"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b29d4986d0da1a27cd35917cdb433672f5c95d7f"},{"fixed":"4991b5a08751e2e82488fb93ae08849b6aea10d9"},{"fixed":"1b2bec4a7dcf5f00b7a1cbeeec8997841d783513"},{"fixed":"9a5fdfb9e57ec3a8ad2b8fce5e5ffa42d53b130e"},{"fixed":"ac5ee99443891bdb161f5539606a66a1b5e72542"},{"fixed":"93627a29d4b66d4a2def938dfb8610cc80ae454b"},{"fixed":"c348ae47d8e65f06429fa41adce9ad986b696766"},{"fixed":"2b62d0611c9af14a16bddf22df2612b4f40eb5a1"},{"fixed":"2d1f7b65f5deedd2e6b09fdc6ea27f8375f24b45"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-53062.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.12.0"},{"fixed":"5.10.258"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.141"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-53062.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}