{"id":"CVE-2026-53125","title":"md: fix array_state=clear sysfs deadlock","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 9e59d609763f70a992a8f3808dabcce60f14eb5c < 62c44566da7493ee48ef17e8507bb798338a07cb","Linux >= 9e59d609763f70a992a8f3808dabcce60f14eb5c < 92ad0ec509ffb188d8f849b63148664df37b4a52","Linux >= 9e59d609763f70a992a8f3808dabcce60f14eb5c < 2aa72276fab9851dbd59c2daeb4b590c5a113908","Linux 6.17"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:20:06.493244Z"},"published":"2026-06-24","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:24:02.851Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53125","references":[{"url":"https://git.kernel.org/stable/c/62c44566da7493ee48ef17e8507bb798338a07cb"},{"url":"https://git.kernel.org/stable/c/92ad0ec509ffb188d8f849b63148664df37b4a52"},{"url":"https://git.kernel.org/stable/c/2aa72276fab9851dbd59c2daeb4b590c5a113908"}],"tags":["cve.org"],"epss":0.00124,"epssPercentile":0.02118,"ingestedAt":"2026-11-06T16:57:43.286Z","slug":"CVE-2026-53125","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 9e59d609763f70a992a8f3808dabcce60f14eb5c < 62c44566da7493ee48ef17e8507bb798338a07cb`\n- `Linux >= 9e59d609763f70a992a8f3808dabcce60f14eb5c < 92ad0ec509ffb188d8f849b63148664df37b4a52`\n- `Linux >= 9e59d609763f70a992a8f3808dabcce60f14eb5c < 2aa72276fab9851dbd59c2daeb4b590c5a113908`\n- `Linux 6.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}