{"cve":"CVE-2026-53125","nvd":{"published":"2026-06-24T17:17:27.770","modified":"2026-07-23T20:53:17.777","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd: fix array_state=clear sysfs deadlock\n\nWhen \"clear\" is written to array_state, md_attr_store() breaks sysfs\nactive protection so the array can delete itself from its own sysfs\nstore method.\n\nHowever, md_attr_store() currently drops the mddev reference before\ncalling sysfs_unbreak_active_protection(). Once do_md_stop(..., 0)\nhas made the mddev eligible for delayed deletion, the temporary\nkobject reference taken by sysfs_break_active_protection() can become\nthe last kobject reference protecting the md kobject.\n\nThat allows sysfs_unbreak_active_protection() to drop the last\nkobject reference from the current sysfs writer context. kobject\nteardown then recurses into kernfs removal while the current sysfs\nnode is still being unwound, and lockdep reports recursive locking on\nkn->active with kernfs_drain() in the call chain.\n\nReproducer on an existing level:\n1. Create an md0 linear array and activate it:\n   mknod /dev/md0 b 9 0\n   echo none > /sys/block/md0/md/metadata_version\n   echo linear > /sys/block/md0/md/level\n   echo 1 > /sys/block/md0/md/raid_disks\n   echo \"$(cat /sys/class/block/sdb/dev)\" > /sys/block/md0/md/new_dev\n   echo \"$(($(cat /sys/class/block/sdb/size) / 2))\" > \\\n\t/sys/block/md0/md/dev-sdb/size\n   echo 0 > /sys/block/md0/md/dev-sdb/slot\n   echo active > /sys/block/md0/md/array_state\n2. Wait briefly for the array to settle, then clear it:\n   sleep 2\n   echo clear > /sys/block/md0/md/array_state\n\nThe warning looks like:\n\n  WARNING: possible recursive locking detected\n  bash/588 is trying to acquire lock:\n  (kn->active#65) at __kernfs_remove+0x157/0x1d0\n  but task is already holding lock:\n  (kn->active#65) at sysfs_unbreak_active_protection+0x1f/0x40\n  ...\n  Call Trace:\n   kernfs_drain\n   __kernfs_remove\n   kernfs_remove_by_name_ns\n   sysfs_remove_group\n   sysfs_remove_groups\n   __kobject_del\n   kobject_put\n   md_attr_store\n   kernfs_fop_write_iter\n   vfs_write\n   ksys_write\n\nRestore active protection before mddev_put() so the extra sysfs\nkobject reference is dropped while the mddev is still held alive. The\nactual md kobject deletion is then deferred until after the sysfs\nwrite path has fully returned.","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-667"],"references":["https://git.kernel.org/stable/c/2aa72276fab9851dbd59c2daeb4b590c5a113908","https://git.kernel.org/stable/c/62c44566da7493ee48ef17e8507bb798338a07cb","https://git.kernel.org/stable/c/92ad0ec509ffb188d8f849b63148664df37b4a52"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-53125","score":0.00124,"percentile":0.02082,"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."]}