md: fix array_state=clear sysfs deadlock
Summary
| CVE | CVE-2026-53125 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-06-24 17:17:27 UTC |
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| Updated | 2026-06-24 17:17:27 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
md: fix array_state=clear sysfs deadlock
When "clear" is written to array_state, md_attr_store() breaks sysfs
active protection so the array can delete itself from its own sysfs
store method.
However, md_attr_store() currently drops the mddev reference before
calling sysfs_unbreak_active_protection(). Once do_md_stop(..., 0)
has made the mddev eligible for delayed deletion, the temporary
kobject reference taken by sysfs_break_active_protection() can become
the last kobject reference protecting the md kobject.
That allows sysfs_unbreak_active_protection() to drop the last
kobject reference from the current sysfs writer context. kobject
teardown then recurses into kernfs removal while the current sysfs
node is still being unwound, and lockdep reports recursive locking on
kn->active with kernfs_drain() in the call chain.
Reproducer on an existing level:
1. Create an md0 linear array and activate it:
mknod /dev/md0 b 9 0
echo none > /sys/block/md0/md/metadata_version
echo linear > /sys/block/md0/md/level
echo 1 > /sys/block/md0/md/raid_disks
echo "$(cat /sys/class/block/sdb/dev)" > /sys/block/md0/md/new_dev
echo "$(($(cat /sys/class/block/sdb/size) / 2))" > \
/sys/block/md0/md/dev-sdb/size
echo 0 > /sys/block/md0/md/dev-sdb/slot
echo active > /sys/block/md0/md/array_state
2. Wait briefly for the array to settle, then clear it:
sleep 2
echo clear > /sys/block/md0/md/array_state
The warning looks like:
WARNING: possible recursive locking detected
bash/588 is trying to acquire lock:
(kn->active#65) at __kernfs_remove+0x157/0x1d0
but task is already holding lock:
(kn->active#65) at sysfs_unbreak_active_protection+0x1f/0x40
...
Call Trace:
kernfs_drain
__kernfs_remove
kernfs_remove_by_name_ns
sysfs_remove_group
sysfs_remove_groups
__kobject_del
kobject_put
md_attr_store
kernfs_fop_write_iter
vfs_write
ksys_write
Restore active protection before mddev_put() so the extra sysfs
kobject reference is dropped while the mddev is still held alive. The
actual md kobject deletion is then deferred until after the sysfs
write path has fully returned. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 9e59d609763f70a992a8f3808dabcce60f14eb5c 62c44566da7493ee48ef17e8507bb798338a07cb git |
Not specified |
| CNA |
Linux |
Linux |
affected 9e59d609763f70a992a8f3808dabcce60f14eb5c 92ad0ec509ffb188d8f849b63148664df37b4a52 git |
Not specified |
| CNA |
Linux |
Linux |
affected 9e59d609763f70a992a8f3808dabcce60f14eb5c 2aa72276fab9851dbd59c2daeb4b590c5a113908 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6.17 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.17 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.33 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.0.10 7.0.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/2aa72276fab9851dbd59c2daeb4b590c5a113908 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/62c44566da7493ee48ef17e8507bb798338a07cb |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/92ad0ec509ffb188d8f849b63148664df37b4a52 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.
