{"cve":"CVE-2026-53064","nvd":{"published":"2026-06-24T17:17:19.320","modified":"2026-07-21T17:36:29.553","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm cache: fix null-deref with concurrent writes in passthrough mode\n\nIn passthrough mode, when dm-cache starts to invalidate a cache\nentry and bio prison cell lock fails due to concurrent write to\nthe same cached block, mg->cell remains NULL. The error path in\ninvalidate_complete() attempts to unlock and free the cell\nunconditionally, causing a NULL pointer dereference:\n\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nCPU: 0 UID: 0 PID: 134 Comm: fio Not tainted 6.19.0-rc7 #3 PREEMPT\nRIP: 0010:dm_cell_unlock_v2+0x3f/0x210\n<snip>\nCall Trace:\n invalidate_complete+0xef/0x430\n map_bio+0x130f/0x1a10\n cache_map+0x320/0x6b0\n __map_bio+0x458/0x510\n dm_submit_bio+0x40e/0x16d0\n __submit_bio+0x419/0x870\n<snip>\n\nReproduce steps:\n\n1. Create a cache device\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. Promote the first data block into cache\n\nfio --filename=/dev/mapper/cache --name=populate --rw=write --bs=4k \\\n--direct=1 --size=64k\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 first cached block concurrently\n\nfio --filename=/dev/mapper/cache --name test --rw=randwrite --bs=4k \\\n--randrepeat=0 --direct=1 --numjobs=2 --size 64k\n\nFix by checking if mg->cell is valid before attempting to unlock it.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/01264a6a3a3ad7ac1d73443299cd5a9568002454","https://git.kernel.org/stable/c/0aa745fea1f8dc81bcdd0a45e215b6706727b482","https://git.kernel.org/stable/c/25dcc1989c194ba2b5fb6d03cbb9b83814ac0d15","https://git.kernel.org/stable/c/7d1f98d668ee34c1d15bdc0420fdd062f24a27c0","https://git.kernel.org/stable/c/a2635d541a93fd111e743cf14b6275dc81be2abc"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-53064","score":0.00123,"percentile":0.02005,"date":"2026-10-31"},"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."]}